Any way I could have won this game? In this game I thought I played very well, but is there any way I could have won it.

The bottom right doesn’t look very secure. If L and M7 filled it would be vulnerable. If they didn’t defend correctly you might have won, or lost by half a point instead.

Its a great feeling when one experiences a very close game. At the current level of the 2 players, however its probable either side could have won (in 50 different ways) depending on the last endgame mistake made.
But to improve you probably need to look at the opening20 moves, not move 200+ because in such a long game there will have been too many mistakes by both players.
At your level a loss by 1.5 points is as valuable as a win

I did a quick review.