Hi Toaster123. I am sorry you are experiencing so much hurt and pain. Losing a close friend is very hard. But perhaps it is harder if you have experienced past abuse. All of the above recommendations are good. Seeing a school counselor would be something good to do. I would recommend that if you are very shy or not good at talking and discussing things you could write down a list of problems to go over with the counselor.
Sometimes it is just easier to write out our thoughts and feelings than it is to talk about them.

I wish you the best.