I rely on fighting for 90% of my play and I am stuck at 3 kyu on OGS and AGA, although I have yet to attend any AGA tournaments to gauge this, I trust Sensei's library's rank comparison from 2018 as I do have a 1D on Tygem but a 3K on OGS and I haven't been able to rise above either rank on each respective server.

With that in mind: please offer up playing advice that helped you push past a plateau. I'm stuck here for the past 10 years as I really stopped studying the patterns and I never looked at pro games with any real intention beyond just looking at how they played through the game.

When I do, I do play better but I lose the insight as I don't understand why they played they way they played I just copied the moves when and where I saw fit but I can't tell you why a play is best or when to tenuki or hane or in what state of aji/aji-keshi I'm in at any given place in a game and so i lose games in fantastic fashion because of my mistakes.

Advice on getting stronger/wiser in play will be helpful.

Black's problem seems best exemplified with 41. You shouldn't expect to kill with so many weaknesses outside, and the alternative looks much more appealing: protect at O13, then White has to live on the side and you get to attack the three outside stones, probably building points across the top and maybe some additional strength in the centre (if White defends those stones at this point, which might be questionable).

Also, 41 doesn't seem like the best move to kill, but I think that is not the main problem with it.

_________________
A good system naturally covers all corner cases without further effort.

Maybe some harsh advice coming

It is a good idea to just resign when nothing goes your way as happened in this game. It will actually help you improve since you will make much better use of your Go playing and reviewing time. If there is life and death on the board then play it out before resigning (it is good practice) and if you think you can keep the score stable and play a regular game, which you will lose by whatever number of points, then that is usually fine. In the end it is about how you use your practice time.

In this game you could just have resigned at any point after move 95 and spent the remaining 130 moves on a different game.

First, a few minor comments about fuseki:
1) Move 5 was probably better on the left side. It is bigger.
2) After he makes an east-facing shimari in the top left, move 7 is definitely in the wrong place. It should be around K16.
3) Move 17 is inefficient. It strengthens your strong stones. It would have been better to strengthen your Q16 stone by playing O17 or maybe even N17.
4) Move 23 is probably better at Q11. It seems to work better with the high stones that black has elsewhere on the board.

Despite those theoretical innaccuracies, at move 40 you still have a playable game at the high-kyu/low-dan level. Your play is not perfect, but neither is his. ( You have a few cutting points that you have to protect, but he has spent a lot of stones to achieve a rather small group. )

But your game goes down the drain in the forties.

Your general problem is that you attacked from a weak position.
In particular, you ignored move 40, which took away a liberty. You should have played 41 at P12 or O12.
( Harlequin says 41 at O13, which may be optimal shape, but requires perfect technique to follow up )

Have a look at https://senseis.xmp.net/?MakeAFistBeforeStriking
Also, there is a proverb ( which I can't recall exactly ) that says any time your opponent takes half of your group's liberties, or reduces those liberties to three, you should be seriously worried about your group.

Once you let him cut at O12, the game is essentially over. He then has a decisive advantage, and winning is simply a matter of technique. Unfortunately for you, his technique was good enough, and you probably should have resigned someplace between move 58 and move 100.

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Help make L19 more organized. Make an index: https://lifein19x19.com/viewtopic.php?f=14&t=5207

Move 41

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . 3 O X . |
$$ | . . . . . . . . . . . . . 2 X X O X . |
$$ | . . . , . . . . . , . . . . O X X O . |
$$ | . . O . . . . . . . . . . . O O X O . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . 1 . X O 4 . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . X O O O . |
$$ | . . . , . . . . . , . . . . . X X X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . . . . . X X 5 . |
$$ | . . . . . . . . . . . . X X X O O . . |
$$ | . . . . . . . . . . . . . O O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Move 48

Click Here To Show Diagram Code

[go]$$W Easy way
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . 8 . . |
$$ | . . . O . . . . . . . . . . 7 4 O X . |
$$ | . . . . . . . . . . . . . 3 X X O X . |
$$ | . . . , . . . . . , . . . . O X X O . |
$$ | . . O . . . . . . . . . 9 6 O O X O . |
$$ | . . . . . . . . . . . . 5 2 . X O O X |
$$ | . . . . . . . . . . . . 1 X X X O . X |
$$ | . . . . . . . . . . . . . O O X O . . |
$$ | . . . . . . . . . . . . . . X O O O . |
$$ | . . . . . . . . . , . . . . . X X X . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$Wm13
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . O X . X . |
$$ | . . . . . . . . . . . . . O X X . X . |
$$ | . . . , . . . . . , . . O X . X X O c |
$$ | . . O . . . . . . . . . O X . . X O . |
$$ | . . . . . . . . . . . . O X X X O O X |
$$ | . . . . . . . . . . . . O X X X O b X |
$$ | . . . . . . . . . . . . 1 O O X O . a |
$$ | . . . . . . . . . . . . . . X O O O . |
$$ | . . . 5 . . . . . , . 3 . 2 . X X X 4 |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . . . . . X X . . |
$$ | . . . . . . . . . . . . X X X O O . . |
$$ | . . . . . . . . . . . . . O O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]