2: Hard to make a bad move here, yours is fine.
6: White 5 is a bad mistake, white gives black the corner for nothing. It is probably correct to just say 'thank you' and take R18. That leaves white with nothing much, and black with some solid territory and a pincer stone to develop. Your move leaves a terrible weakness at R16 because you are too worried about making normal shapes and assuming white's move is normal.
16: Far too many weaknesses in your shape. R6 seems easiest, but plausibly you can play P4 or something to try and get sente (though you definitely don't have to!). This move is trying to kill the 3-3 invasion, which I'm sure you know shouldn't work, which should make you wonder if you're trying too hard.
24: Your wall is strong, and white has a weakness at R7. I think your extension is thus too small, F3 or C6 seem maybe better. It is more interesting to take the corner and challenge white to invade than to make a small territory from a big wall and give white the corner later.
37: White did not waste a move, this is the normal 3-3 shape. White wants to prevent black's F2 descent in sente.
38: Nooo! Building small territories from big walls! If you want to make a territory here, you need 4 more moves at D9, E6, B10, E5. Are you going to play them all? That would be 4 moves spent to makes about 13 points, 3-4 points per move is as inefficient as an inefficient thing. Instead you should develop a massive moyo from all your strength - wherever white invades, you will attack, and thereby naturally create a massive territory by making white seal it off for you. It is always better to make your opponent spend his moves to help you, not spend yours needlessly. I'm not sure what's best, but you can think about F10, K15, F16, that sort of thing. Think big!
40: What!? What do you think white is going to *do* there?
42: There is no terrible weakness for your 4-4 stone, and seperating things is good.
43: Terrible move for white, he must not know that you shouldn't try to cut the one space jump.
48: 'Dangerous for white?', you just made a weak group whilst letting white almost connect his stones together. M17 seems essential - you cut white, and maybe kill the O17 group, punishing white for trying to cut such a strong connection.
58: Well, you ahe at least made a big wall, though I think white could play better to stop that. But...another 15 points of territory!? That's as much as white made on top for free, don't you want more than that? Like, the entire centre of the board? Thickness is for thinking big with, thickness if for attacking, for inviting your opponent to wander into your destructive trap. Play tengen or something, and eat the whole board.
65: Your oppoent has an unhealthy fondness for these knights moves. Although I haven't commented on it before, every one of them (O7, Q8, N15) has left weaknesses for you to exploit later, in some cases by simply cutting his weak shape. Here, You can simply cut at H4.
66: You can cut before connecting.
68: No! No! No! White just played right in the middle of your strongest area on the entire board, and you say 'oh, yeah, that's probably alive. I'll just play this move white gains me 0 territory and lets white run away'. Play G9, kill, kill, kill.
70: Lose the terrible fear of cuts - in this case, white just has nothing here, the cut doesn't work. J10 seems okay, maybe J9. By attacking on a large scale, even if white lives (not obvious), you can cut N16, peep (or cut) O9, and suddenyl have loads of territory in the top right. This would be the right way to use your thickness.
71: Another rubbishy knight's move. White has no respect for the weakness of his groups, but this is working because you have a terrible fear of the weakest stones

72: Not greedy, and it aims at the R7 cut which is strong so it's probably sente. It seems more fun to attack, though, and maybe exploit this aji differently later.
<some exchanges happen here. Both players continue to miss the point of weak stones>
90: Terrible, you can and should play M18 first. Then white isn't even alive in the upper right.
94: Why does this look like a mistake?
96: Appalling, wht is this move for? It connects two live groups together, that's nice, but it doesn't stop the P13 group from running and connecting. White is pleading with you to attack all his weak groups on a very large scale, why won't you listen?
<black actually attacks, some exchanges, but black only plays to keep his moveo and, incredible, white makes some territory in the middle right. White can play P10 at (for instance) move 141, and be surprised that he got anything at all.
In the end, black wins, but the overall strategy was terrible and you must lose your fear of white. Hope this helps.