I don't see that you lost too much. White looked a little ahead for most of the endgame.
Of course, the final score is wrong because black eventually needs to play T17, so you got a gift from white.
(Probably just should have captured at T17 instead of extending, anyway.)I think at 161 you can play L1 and handle it, or is that too dangerous?
If 239 is at J12 instead of H13, then you get to keep K11 as a point. In the real game, you connect K11 as a teire at move 247 rather than capturing the ko at G7.
But these are all pretty small. Others may find bigger things, but maybe looking earlier in the game for mistakes a good idea.