Suddenly can't remember anything

Hey guys, I've got this problem when I can't remember all my study stuff. I'm really frustrated, so I'm going to say a lot, so please read to the end. I'm a ninth grader. I've always been in the top ten in my class with A's and B's. I always stayed organized and got my work done. I had a little trouble with ninth grade so far, but it got much worse when we started midterms. I suddenly can't remember anything. When I take a test, I will know the right answer, but I can't remember what the question was and I end up counting the rows and going back. I get anxious, I get frustrated and I give up. I can't remember anything for this test. I study, and as soon as I start reviewing practice tests, I remember what I studied. I go to school the next day, and I don't remember the practice questions OR what I studied. I did bad on my math midterm. I really want to kill myself rn. I feel like I will never do well in school. My friends do better than me. I feel like the dumb one. I'm frustrated that I can't do better, but I know I can do better if I can remember. I just need to figure out how to remember. <br><br>Please help.