Harassment by wife's parents, maternal grand parents and sisters

I am a research scholar at NIT Patna. I am a hindu and married to a woman in same city (Patna), having a single male child (aged 5, LKG). My marriage is based on a pile of lies which my family failed to intercept before marriage. Wife is just 12th pass and can't discriminate between good and bad. Very short tempered and has also been diagnosed with Borderline Personality Disorder which my in-laws never accept. They did not let the prescribed treatment go on. Worse thing is that my wife uses dirty abuses for me and my family. She has even raised hands on my parents when we were living with them. Currently we live in a rented house. She always treats me like her pet. Love and romance are worthless things for her. I have much to say but space is limited. My actual problem is her family members who talk to her daily on the phone and encourage her nasty behavior. Her father threatened me and my father two times to manhandle. She can be molded if they stop encouraging her. What should I do?