If you find difficulty talking to your mom or getting her to help you find a psychiatrist then perhaps a school councilor? They are very good at what they do and sometimes it's easier talking to strangers about all this sort of stuff. (Which I'm guessing is one reason you're posting it here ^-^)

You might be stressing about school a little too much, maybe try relaxing? I find that studying for tests and exams will only get you so far but paying attention in class will take you all the way. If that still isn't working, maybe try and look up different studying techniques? Perhaps you're just not using the right ones for the way your brain works?

You seem like a very nice person and it's a bit sad to hear you've hurt yourself but I'm glad that you did share this information and also that you're managing to get control over it quickly! Way to rock out! ^_^ That's just about the best advice I can think of and I hope it helps.

I give LOTS of internet hugs for you, and the best of wishes. Good luck!