Geez - family troubles are the worse I think, of all the people that should be there the most for you are against you. I think ur right to distant yourself from them. Even maybe your son too needs to be removed from the situation. Do you "have" to live close to everone or do you have the option of moving far far way? My parents did that as my fathers step-dad was very abusive and the first chance he got he was gone. I never knew my "grand-parents" which was hard, but from the history I hear, it was probably the safest idea for me.

Good luck and your right to limit any contact with them. sometimes the squicky (sp) wheel get the attention but not always the right type.