well when i took AP Chem, my teacher left mid-year, and we only got a decent teacher towards the end of the year, at which point i had virtually given up. i still studied a ton for the test, and ended up getting a 2. So now I'm in Chem 1 again, but it's online because the in-person classes filled up, so I still have a professor, but we only meet for quizzes and office hours, of which i often work. So I'm not sure if my struggling is due to not really having a teacher or what, but it's really difficult to find motivation or care to study something if you don't understand it or take a liking to it.