Do you have a therapist? I think it's important in your case. If your parents refuse, you can call child services. It's highly unlikely you'd get removed from a home, but they could advocate for you in getting a therapist, get dad to stop saying negative things about mom (that's actually illegal some places or during custody battles, it is damaging to the kids to hear negative comments about other parent), and get mom to be more aware of the conflict going on with your brother. I'm a parent of 3, and have child services "investigate" for the usualy bipolar reasons. They have put a sort of fire under my butt to do things I need to be doing, like therapists for the kids.