So, first, contact support and explain what happened, the dates that your account(s) was/were compromised, ask if they can help with that issue, and be truthful as to what happened. In regards to the actual punishment, ask them to look at your previous track record, acknowledge that your account is your responsibility and plead that they simply reduce the punishment.
Secondly, holy crap, your classmates sound like absolute psychopaths. You MAY want to look into professional counseling for them.
Thirdly, you've stated you're 13. Are you typing your passwords in class? If so, stop that crap. Concentrate on your studies. If you're typing them outside class, do people record individuals typing passwords now-a-days? This feels like the proverbial "Is this what kids are doing now?". Anyway, the person you're chilling with seems to have a few screws loose. Unless this person is a close, long-time friend, just stop interacting with them. You don't need that type of negativity in your life.