It's not for a lack of being prepared either. After they've been seared into my brain, I've done some of the problems on the test afterwards with little difficulty.
I do all the homework, take notes, all the stuff you're supposed to for college classes, but when I get to tests I just blank. Then start getting frustrated with myself, which starts a negative feedback loop until I'm sobbing into my desk.

What's the point of trying if I always mess up the important parts? I just feel so useless.