Well, yeah, this was a squeaker. Too much excitement for one game.
Yes, you did not very well before the kill, and you lost points you did not need to in the fight. And after the kill you played much to passively. You do not have to play passively to play solidly. Even when you had the game sewn up, you gave your opponent chances to win.
I have pointed out .some tesuji for you to keep in mind.
There were times when you made obviously small plays when there were big ones staring you in the face. May I suggest developing the habit of taking a second or two to simply look at the whole board. Doing so will help break your focus on areas where the plays are small.
One note. Victor, your opponent, was way too stubborn. You were not stubborn enough.
(;CA[UTF-8]ST[2]AP[GOWrite:3.0.15]GM[1]FF[4]SZ[19]WR[7k]CP[online-go.com]PC[OGS: https://online-go.com/game/17017515]RU[Japanese]BR[9k]PW[ВикторБирюков]RE[B+11.50]GN[ ]PB[Ian Butler]TM[1200]DT[2019-03-16]KM[6.50]FG[259:]PM[2]OT[5x30 byo-yomi]
;B[pd];W[qp];B[dd];W[do]
(
;B[op]C[*** See variation.]
;W[cf];B[fc]
;C[Leela wants A or B.
*** A is joseki when White has an extension in the middle of the left side.]W[ci]LB[cq:A][qq:B]
(
;B[dq]C[*** See variation.]
;C[No idea about this joseki.
*** The inside attachment looks best.]W[eq]
(
;B[co]C[*** Thin. Also, invites White to strengthen the left side. See variation.]
;W[cn];B[cp];W[dn];B[er]
(
;C[*** See variation.]W[fq]
(
;B[ce]C[*** Mistake, for three reasons. Mainly, it allows White to make a wraparound enclosure on the bottom left conren. Also, White can ignore this play. Third, if White does stand, it strengthens White's left side.
See variation.]
;C[*** Good.]W[fr]
(
;B[cr]C[*** Unnecessary gote. See variations.]
;W[lp]
(
;B[pn]C[No idea about this pincering joseki.
*** This is playable. Also see variations for usual plays.]
;W[qn]
;B[qm]C[*** Good.]
;C[*** Not good. Invites Black's next play.]W[po]
;B[oo];W[pm];B[on]
;C[Leela wants A for both sides for a whole while now.
*** Humans do, too.]W[ql]LB[rm:A]
(
;B[df]C[*** Big mistake to allow the ponnuki. Ponnuki very lucky!
See variation.]
(
;C[*** Bad mistake for White, too. See variation.]W[nc]
(
;B[lc]C[*** See variation.]
(
;C[*** See variation.]W[qc]
;B[pc]C[*** Keeping White separated is good.]
(
;C[*** See variation.]W[qd]
;B[pe]
(
;C[*** See variation.]W[rf]
(
;B[ln]C[*** See variation.]
(
;C[*** Sorry to be boring, but see variation.]W[jc]
(
;B[kd]C[*** Ditto.]
(
;C[*** See variations.]W[id]
(
;B[jf]C[*** Looks best locally, but see variation., OC.]
;W[ne]
(
;B[nb]C[Cowering in fear.
*** Oops! Bad mistake. Suu variations.]
;W[ob]
(
;B[oc]C[*** Oops again! See variation.]
;W[mb]
;B[nd]C[*** C'est la vie1]
;W[mc];B[md]
;C[*** Sigh!]W[lb]
(
;B[pb]C[*** Whati's the point? Black is connected, White is OK. See variation.]
;C[ ]W[ol]
(
;B[qg]C[*** See variation.]
;W[qf];B[pf]
;C[*** Passive.]W[rg]
;B[pk]C[*** Aji keshi. Bad.]
;C[*** Good!]W[rm]
;B[qq];W[rq]
(
;B[qr]C[*** Passive. See variation.]
;C[*** Good!]W[kc]
;B[cg]C[*** Surely the connection is good.]
(
;C[*** Huh? See variation.]W[qh]
(
;B[dj]C[*** See variation.]
;W[di];B[fj];W[ej];B[ek];W[ei]
(
;B[fk]C[*** see variation.]
;C[*** Bad mistake. White needs to connect on the left side.]W[nj]
(
;B[ko]C[*** Very inefficient. Makes no use of Black's wall. See variation.]
;W[kp]
;B[ho]C[*** Lax.]
;W[jo];B[jn];W[io];B[in];W[hn]
;B[hp]C[*** Good"]
;W[iq]
(
;B[fo]C[*** Bad slip. See variation.]
;W[gn];B[fn]
;C[Here I make a first ridiculous mistake. I fail to see an obvious ladder.]W[go]
(
;B[ck]C[And so I forgo my stones. Black is behind.
*** Even if you have to sacrifice your stones, the block is good, to make White go to some trouble to capture them.]
;C[*** Good.]W[fm]
(
;B[gh]C[*** See variation.]
;W[km];B[kn]
;C[*** Too stubborn. Not good.]W[fi]
;B[gi];W[gj]
(
;B[hk]C[*** See variation.]
;W[hj]
;B[ij]C[*** Good.]
;W[hi];B[hh]C[ ];W[ii];B[gk]
;C[Leela suggests A.
*** But of course. White is too stubborn. Not good.]W[fg]LB[ji:A]
(
;B[gf]C[*** Yes, the ladder looks better.]
;C[*** Too stubborn.]W[gg]
(
;B[fh]C[*** Not stubborn enough. See variation.]
;C[*** It's only 5 stones, let them go.]W[eh]
;B[hg]C[*** Yes!]
;C[*** Bad to worse.]W[ef]
(
;B[ff]C[*** see variations.]
;C[*** Aji keshi. White might want to use that stone later.]W[dg]
;B[bf]
;C[*** Menschliches, allzumenschliches!]W[ee]
(
;B[he]C[*** There is a better way to protect that cutting point. See variation.]
;W[fd]
;B[gc]C[*** Good.]
;W[gd];B[hd];W[ec];B[ed];W[de];B[cd];W[cf]
(
;B[bg]C[*** Singing, I only have one eye for you.
See variation.]
;W[bk];B[bl];W[cj]
(
;B[dk]C[*** See variation.]
;C[if black at A, can white get out?]W[bi]LB[ch:A]
(
;B[ak]C[only option
*** No, Black can kill. See second variation.]
;C[likewise]W[aj]
;B[bj]
;C["bad" threat.]W[hc]
(
;B[ai]C[*** De l'audace! See variation.]
;W[fb]
;B[fe]C[black cuts off the 2 stones.]
;W[gb]
;B[ji]C[Leela thinks this really small. In fact, she has white at the advantage right now. I had not expected that.
*** Well, you have taken hits on all sides.]
;C[*** Overplay.]W[if]
(
;B[hf]C[*** Passive. see varaition.]
;W[je]
(
;B[jg]C[*** Passive. see variations.]
;W[ke]
(
;B[oa]C[*** See variation.]
(
;C[*** Overplay. See variatoin.]W[oe]
(
;B[od]C[*** Passive. See variation.]
;C[*** Underplay.]W[qb]
(
;B[me]C[*** See variations. Very important.]
;W[ng]
(
;B[mf]C[*** Bad shape. Do you want to peep at a bamboo joint? See variation.]
;C[*** White not only escapes, but enlarges his territory on the right side.]W[og]
(
;B[lg]C[*** Not just passive, timid. See variation.]
(
;C[*** Maybe the gome losing play. See variation.]W[rr]
;B[pp];W[qo]
(
;B[or]C[too safe
*** Right. The keima looks best. It not only makes "territory" it threatens to intrude into White's territory.]
;W[mr]
(
;B[nq]C[*** And your point is?
See variation.]
(
;C[*** Silly. See variation.]W[mq]
(
;B[dp]C[*** Onnly threatens one weakness. See variation.]
;C[*** Oblivious to the danger. Is thiis the game losing move?]W[pq]
;B[ep]C[*** Looks ilke it, huh?]
;C[*** Stubborn.]W[pr]
(
;B[il]C[*** See variation.]
;W[mn]
(
;B[mo]C[*** Time for the clinche. See variation.]
;W[lo]
;B[mm]C[white sees something here that isn't there.
*** Another clincher.]
;W[lm];B[nn];W[im];B[jm];W[hm]
(
;B[jl]C[and so black has the lead again.
*** Time for the clincher. See variation.]
;W[gp]
;B[em]C[another few stones captured
*** Another clincher.]
;W[en];B[pg];W[fp];B[eo];W[es]
;B[dr]C[*** Playing it safe.]
;W[bn]
(
;B[bo]C[*** Ditto. But see variation.]
;W[cb];B[bc];W[bb]
;B[ph]C[Good.
*** Indeed.]
;W[ah];B[aj];W[bh]
;B[df]C[and suddenly I find myself in a ko.Leela has black ahead comfortably, though.]
;W[el];B[dm];W[cf];B[ac];W[ag];B[df];W[dl];B[cm];W[cf];B[db];W[dc];B[df];W[bm];B[cl];W[cf];B[eg];W[fg];B[df];W[al];B[am];W[cf]
(
;B[dh]C[*** A potential losing move. Throws away an eye and a dame. See variation.]
;W[ch]
;B[af]C[Mistake! Momentary loss of concentration and wrongful view. I thought this was an atari, but white also has a liberty at E13.I'm ashamed to admit I overlooked it.]
(
;C[*** See variation.]W[be]
;B[df];W[lf]
;B[eg]C[Leela agrees.
*** Hell yes!]
;W[mg];B[qi];W[rh]
(
;B[ok]C[*** See variation. This game has been too exciting.]
;W[nk];B[oi];W[ni]
(
;B[oh]C[*** Possible mistake. See variation.]
(
;C[*** See variaition.]W[nh]
;B[pj]C[no...
*** You are right.]
;W[ri];B[rj]
(
;C[*** See variation.]W[rk]
;B[le]C[Just filling my own liberties.]
;W[kf];B[nl]C[Good.];W[kg]
(
;B[oj]C[But I chicken out, now. Don't read out the capturing race, instead just go to live. See var for capturing race.However, black has nothing to fear. This move is ridiculous. However, I thought myself ahead and this was the safe move. I didn't need to kill that bunch of white stones to win.
*** Living is good enough.]
;W[sj];B[qj];W[jh];B[ig];W[ki];B[jj];W[la];B[na]
;C[Very bad move. Takes away a point for himself.]W[ra]
;B[pa];W[ml];B[nm];W[lk];B[ll];W[kl];B[kk];W[ll];B[lj];W[mk]
(
;B[kj];W[lh];B[pl];W[ld];B[qa];W[sb];B[qe];W[re];B[ds];W[qs];B[nr];W[mp];B[ms];W[np];B[oq];W[ls];B[ns];W[kr];B[fs];W[gs];B[es];W[hr];B[fl];W[no];B[mn];W[qm];B[om];W[kh];B[ih];W[ab];B[cc];W[jd];B[ie];W[li];B[gm];W[mj];B[hl]
(
;C[minus one point, I believe.]W[hq]
;B[tt];W[tt]
)
(
;W[tt];B[gq];W[gr]
)
)
(
;B[li]C[I wanted to do this, but just doesn't work.]
(
;W[lh];B[kj]
)
(
;W[kh];B[lh];W[kj];B[jk];W[ih]
)
)
)
(
;B[lh];W[ml];B[nm];W[pl]
;B[mk]C[Although I see black will win it.]
)
)
(
;C[*** No ey here.]W[qk]
;B[nl]C[*** The cut to the rescue. Black can win the semeai or connect if WHite manages to live. . . .]
;C[*** Because to have space for two eyes White must make this play.]W[ml]
;B[nm]
;C[*** And now Black can connect.]W[lk]
)
)
(
;C[*** Ouch!]W[oj]
(
;B[pj]
;C[*** How does Black live?]W[nl]
)
(
;B[nh];W[mh];B[mi];W[lh];B[kg];W[li];B[lj];W[mj];B[pj]
;C[*** All reads leat to Rome.]W[nl]
)
)
)
(
;B[nl]C[*** Prevents White from connecting. Difficult position.]
)
)
(
;B[nf]
(
;W[of]
(
;B[ni]C[*** Tesuji.
You don't need the tesuji, eh? See variation.]
;W[mi]
(
;B[oh]
(
;W[kg];B[lh];W[mh];B[mj];W[lj];B[mk];W[kh]
;B[nk]C[*** Easy life and a little territory.]
)
(
;W[mj];B[mh]
)
)
(
;B[mh];W[lh];B[nh];W[kg];B[oh];W[lg];B[oj];W[nk];B[qk]
)
)
(
;B[mh];W[lh];B[nh];W[kg];B[oh];W[lg];B[oj];W[ok];B[mj]
(
;W[nk];B[pj]
(
;W[ni];B[mi]
)
(
;W[mi];B[ni]
)
)
(
;W[pj];B[oi];W[qj];B[nk]
)
)
)
(
;W[oi];B[of];W[pi];B[oh]
(
;W[lh];B[ni];W[oj];B[kg];W[mi];B[nh];W[ml];B[ll];W[lk]
;B[kk]C[*** Snapback.]
;W[nm];B[mn];W[lj];B[mh]
)
(
;W[nh];B[mi];W[ni];B[nk];W[ok];B[mj]
)
)
)
)
(
;W[df];B[be];W[ad];B[gg]
)
)
(
;B[gg];W[af];B[ae];W[be];B[bd];W[ch]
;B[be]C[*** If necessary.]
;W[eg];B[df]
)
)
(
;B[bq]C[*** More obviously alive, perhaps.]
)
)
(
;B[gp];W[fp];B[gm];W[gl];B[hl];W[gm];B[em]
)
)
(
;B[gp]
)
)
(
;B[gp]C[*** The clincher. Countinue, please.]
;W[fp]
;B[gm]C[*** A tesuji to remember.]
;W[hm];B[im];W[gl];B[hl];W[gm]
;B[em]C[*** Bingo!]
)
)
(
;B[em];W[fp];B[gm];W[hm];B[dp];W[en];B[fl];W[ep]
)
)
(
;C[*** Nails down the game. Pretty much, anyway.]W[gm]
)
)
(
;B[em];W[fp];B[en];W[dm];B[el];W[dp]
;B[gp]C[*** Gimme those stones.]
;C[*** How about this corner?]W[bq]
;B[cq];W[bn]
;B[br]C[*** AOK.]
)
)
(
;B[mq];W[or];B[pr];W[mr]
)
)
(
;C[*** Big.]W[nq]
)
)
(
;B[pg]
;C[*** Big. But . . .]W[ph]
;B[em]C[*** Black takes sente.]
)
)
(
;B[og]C[*** Prevents the bamboo joint and threatens to capture the two stones.]
;W[nf];B[lf]
;C[*** Balck can play elsewhere.]W[nh]
)
)
(
;B[mf]C[*** Not best, but it securely captures the two stones in a net. One to remember.
Edit: My hallucination, but this still may be best.]
;W[me];B[le];W[lf];B[ld];W[nf];B[mg];W[ng];B[kf]
;C[*** Just to show the most stubborn resistance. Does not work.]W[lg]
;B[mh];W[lh];B[nh];W[og];B[oh];W[pg]
;B[li]C[*** Bingo!]
)
(
;B[ng]C[*** Probably best, but it could easily lead to a fight.]
)
)
(
;B[qb]C[*** Easy life.]
;C[*** And the cut is no good.]W[od]
;B[me];W[nf];B[lf]
)
)
(
;C[*** Bottom side is big now.]W[nq]
;B[pp];W[qo];B[or]
)
)
(
;B[me]C[*** More potential for territory here.]
;W[ng]
;B[nf]C[*** For instance.]
)
)
(
;B[em];W[hm];B[ep];W[fp];B[eo]
)
(
;B[kf]C[*** Better locally. Solid.]
)
)
(
;B[ie]C[*** This is solid.]
)
)
(
;B[hb];W[bk]
;B[al]C[*** No problem.]
;W[cl];B[cm];W[dl];B[dm];W[el];B[em];W[fl];B[gm]
)
)
(
;B[ch]
(
;W[bm];B[ak];W[aj];B[bj]
)
(
;W[cl];B[ak];W[bj];B[bn];W[bm];B[am];W[al]
)
)
(
;B[aj];W[ak];B[ch]
(
;W[cl];B[al];W[bj];B[cm];W[dl];B[dm];W[el];B[em];W[fl];B[gm]
)
(
;W[ik];B[il];W[jj];B[hm];W[gm];B[bn]
)
)
)
(
;B[cl];W[dk];B[dl];W[el];B[em];W[fl];B[gm]
)
)
(
;B[bh]C[*** Maybe a little bit better.]
)
)
(
;B[eg]
;C[*** What cutting point?]W[fg]
)
)
(
;B[ji]C[*** Still big.]
)
(
;B[dg]C[*** the peep is better locally, as it prevents the cut, as well.]
)
)
(
;B[hg]
)
)
(
;B[ji]
(
;W[ih];B[ig]
)
(
;W[gf];B[fh];W[eh];B[eg];W[ih];B[ig];W[hg];B[jh];W[gg]
)
(
;W[eg];B[he];W[ig];B[ih];W[gg];B[hg];W[hf];B[ge]
)
)
)
(
;B[em]C[*** If you bolster your stones on the side and threaten his other stones, you do not need to worry about his single cutting stone.]
;W[gl];B[gk]
(
;W[hl];B[fl];W[gm];B[hk]
;C[*** He needs to worry about his three stones.]W[dl]
;B[dk]
)
(
;W[hj];B[hk];W[dl];B[dk];W[ij]
;B[gp]C[*** Uh-oh!]
;W[hm];B[im]
)
)
)
(
;B[em]C[*** Show a little stubbornness.]
;W[gm];B[gh]
)
)
(
;B[gp];W[fp];B[hm];W[gm];B[gl];W[fm];B[em];W[en];B[fl]
)
)
(
;B[gn]C[*** Take the fight to your turf, where you have the advantage.]
)
)
(
;B[ck]C[*** Banzai!]
)
)
(
;B[gl]C[*** Lighter play, better shape.]
)
)
(
;B[jq]C[*** There is more room onthe bottom side, and the Black thickness is stronger.]
)
)
(
;W[ld];B[le]
;C[*** Let's play!]W[me]
)
)
(
;B[pp]C[*** Get it while you can.]
;W[qo]
;B[kq]C[*** Tesuji.]
;C[*** White escapes.]W[kp]
;B[lq]
(
;W[jq];B[jr];W[iq];B[ir];W[hq];B[jo];W[jp]
)
(
;W[mq];B[mr];W[jq];B[mp];W[jp]
)
)
)
(
;B[rm]C[*** Still good as a sacrifice, depending on which way White replies.]
)
)
(
;B[rm]C[*** Still here.]
)
)
(
;B[pb];W[mb]
;B[lb]C[*** Important to keep White separated.]
;C[*** If White jumps out, . . .]W[ng]
;B[nd]C[*** tesuji.]
)
)
(
;B[rm]
)
(
;B[qf]C[*** Better locally. Leaning atatck.]
(
;W[qe]
;B[pf]C[*** Black has been strengthened.]
)
(
;W[rg];B[qb];W[rb];B[ob]
)
)
)
(
;B[rm]
)
)
(
;C[*** Of course.]W[rm]
)
(
;C[*** Looks to connect either wai.]W[nb]
)
)
(
;B[rm]
)
)
(
;W[rm]
)
)
(
;B[rm]
)
)
(
;W[rm]
)
)
(
;C[*** Ponnuki very lucky.]W[rm]
)
)
(
;C[*** Of course.]W[rm]
)
)
(
;B[rm]C[*** What else?]
)
)
(
;W[rm]
;B[qq]C[*** Now Black needs to tend to his group.]
;W[rq];B[pp];W[qo]
;B[ln]C[*** For instance.]
)
)
(
;B[rm]C[*** Make two.]
;C[*** Then throw away.]W[pl]
;B[qq];W[rn]
;B[rp]C[*** One usual continuation.]
)
)
(
;B[qo]
)
(
;B[pm]
)
)
(
;B[bn];W[bm]
;B[bo]C[*** Better locally. Leaves a weakness for White.]
)
(
;B[df]C[*** Consistent.]
)
(
;B[qq]C[*** Also big.]
)
)
(
;B[fr];W[dp];B[cq]
;C[*** Black still has some play on the bottom side.]W[hq]
)
)
(
;C[*** The bots prefer this play.]W[fr]
;B[ep];W[fq]
;B[dp]C[*** Even though Black connects out.]
;C[*** A good move for White.]W[go]
)
)
(
;B[er];W[ep]
;B[fq]C[*** Joseki.]
;W[fr]
;B[gr]C[*** Capture the cutting stone.]
;W[dr];B[fs];W[cq]
)
)
(
;B[cq]
(
;W[eq]
;B[bo]C[*** Black intrudes into the left side.]
)
(
;W[cp];B[dq];W[ep]
;B[fr]C[*** The White left side moyo is too big, and has a weakness at C-06.]
)
)
)
(
;B[dq]C[*** AlphaGo prefers this play. Me, too, although the other corner approach is playable. Why do I prefer this play? See continuation and next variation.]
;W[nq]
)
(
;B[op]
;C[*** This enclosure, which AlphaGo also likes, aims at the Black stone in the bottom right.]W[dq]
)
)
I made lot of comments. As always, there is no guarantee of correctness.

Edit: Added a few variations. Including a kill without ko.
Edit2: Corrected hallucination.
