tired plover
I think you are just a pessimist. I didn't find a proper reason to be "depressed" or anything stupid like "I want to kill myself"
If you're worried about not getting a grade your parents won't approve of, just study harder and keep revising or maybe do some exercises on the subject you have an exam on to make sure you studied well.
If you don't play a sport, you should try playing one. Try boxing, hit the gym, and have good nutrition.