I truly feel for you, as I had a student in the exact same position in one of my classes. I called in the parents and said that the child was suffering mental abuse. It was also affecting her relationships with other people and her schoolwork. The principal and deputy knew what I did and I had their support. All was documented, as by law. It was a wake up call for the parents to get help.
Do make a tape, as BPT said. Your parents will not appreciate this in the beginning but,it must be done, for your sake and any other siblings.
Aries gave you phenominal advice. Write them a letter and give them each a seperate letter.
Maybe you can go away for shabbos to friends or relatives/grandparents. Get more involved in outside school activities, i.e. swimming, start a rosh chodesh drama club in school, an art class, choir. Keep busy doing chesed. Start a home economics class with baking to sell for snacks etc.
We are all here for you in the CR. You just need to ask.
May H’KBH grant you to have much koach, gevura, happiness, menuchas hanefesh ve guf and may you have much siyata dishmaya with much yiras shamayim, with much shalom and shalvah to guide you always on the right path and to make the right decisions kol yemay chayach! Amen!