Well, I'm still at school (high school) and I always feel that way.. It definitely has something to do with your anxiety (most likely)

Also, I'm not sure, but I'd say it has to do with how you grow up during school... did you feel scared/anxious, usually? Were you afraid of your teacher? And what about your parents?

Anyway, I totally get you. I'm sorry you're struggling so much and I wish I could help you