I know it's easier said than done but, maybe now would be the time to tell her you're just not going to let her make you feel the way she does anymore. That this is about YOU, not her. Then, ignore her. Your dad loves you and i'm certain that now he knows what's happenning he'll protect you from it as much as he can. Sure your mums going to stamp her feet and screech her voice but at the end of the day, it's just an attention seeking tactic. Because people are focused on you it's taking the attention away from her. She won't like it. (my mum is the same as yours )
Your dad knows where you are so he can come and see you whenever he likes.