So I've kind of been in a bit of a rut lately, I've lost my last 9 games by pretty significant amounts (the one before this was against the same person, I lost by about 67 I think), and I'm not exactly sure why I'm doing so poorly. In this game I think I put off a move like N 11 for too long, and once my opponent came into my area I just kind of threw stones around trying to hold him off, but I failed pretty badly at that. Later on I was just trying moves that I felt were pretty obvious, but hoping my opponent wouldn't notice, which is a terrible way to play. Black 173 at N9 would have been much better than L7, that was really careless. I'm also wondering if I could have killed that group on the left, Black 195 felt like a stupid move right after I made it, I was thinking B13 would have been better, but I'm not sure. I don't know, I felt like I was doing really well at the start, but I just fell apart mid game.

At move 97 you can do something better than defend a single stone.

Hint:

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what about black 131 at R12? Or even R8. (or both).

I see no reason to give white the entire right side.

Yes. Better to think your opponent will see everything, so you strive for moves that will work despite his best play.
Mostly it was problems with your basics: basic shapes, basic tesujis, basic strategic ideas.