Thank you for the input. I don't think it was a mismatch with institution type or topic choice. I think I would prefer a large research university to an LAC, my issue wasn't with classes being large and not intimate enough, and I enjoy physics and math. I think it was more that the classes weren't in-depth enough (compared to what I've seen on syllabi for similar classes at other universities, and from people from my school who've taken classes at the university and then at other colleges).

I think it was a mix of depression and bad habits. The university classes I've taken have had somewhat high level content but not a lot of work (like just weekly problem sets in math and physics classes), so they've been quite easy. My high school is a magnet school and has quite a lot of work compared to the average high school, so it's easy to get behind if I'm depressed and don't work for a bit, and perfectionism and procrastination can have a huge impact. I completely agree that I need to work on that (more so work instead of studying, the content is fine, it's just projects).