My own father that i used to love mentally abused me without knowing.Like calling me fat and ugly and other mean stuff but idk what to do i am only 11

I shouldn't even be on this site but i feel like i might just go in an eternal mental breakdown and i am scared that things cannot change plus my dad is being abusive to mom but i can't do anything since he'll definitely hit me and i ended up developing PTSD from it so i am terrified by the fact that things might get worse..Can anybody who has lived this kind of experience or knows something about it help me ? I can't report him to the police because he is the only one who can support our family and because i do not want to traumatise my little sister she just turned 6 and i don't want her to grow up like her big sister:scared of the world and cant manage to get friends and probably is a total failure. The reason i am still here is for the people that actually love me as much as i love them. Cried 3 times while making this.Goodbye.Also i am not 26-30 it's just because i am not supposed to tell my age to people i dont know.