Should i move in wiht my real dad?

things are SOOPER ruff with meh mum.we got into it the other night she was drunk and she almost kicked me out....well she did then let me back in.i dont wanto to deal with this anymore.shes insane and i have problems she seems to think are stupid;ex. i cut;i have suicidal thought;eating disorders and so on.how should i go about this?how should i ask my dad and stepmom and how should i tell my mom without her freaking?i wrote her a letter but i am not sure when to give it to her.