This is very tricky, I have no real ideas to suggest other than to be honest about what I would do in your situation - I'd go to my gp and get a short term dose of diazapam to deal with the anxiety and fear and overwhelming emotion. I'd make up some crap about having sudden dental pain and being scared of the dentist to get it. Not ideal but may keep you safe?

The only other thing I can think of is could you possibly bring any friends with you on an outing to the cinema or for dinner? They might inspire your parents to be a bit more civil, and you might feel safer with friends around?

Hope you are okay. Hang in there! It's only a temporary situation, it will be over soon.