Divorce with Child Custody

We are Married since 4 years and has a Daughter of 3 years. Since starting my wife is very Arrogant and Of Rude Behaviour.. Any time on any reason she gets arogant and start misbehaving, fighting and Arguing with me and With my Family as well... I informed her Parents many time about this and asked them to come and discuss about the Matter but they had never talked in this regard.. Instead her mother is keep on Encouraging her to keep doing all these things. Recently my Mother expired due to illness. During 13 Days of my Mother death also she had continue doing all these things, I called her father at that time and again he had not shown any response. In these 4 years 3 time my Wife tried to hit me. I want Divorce and also want custody of my 3 year old daughter. My wife has sudden moond swings, any time she gets angry anytime she gets normal If any 2 or more people taking with eachothere then she thinks they are discussing about her. She keeps on doubting everyone that they are discussing about her. And she keeps on arguing with me ... Please suggest me what to do.. How can I get divorce and custody of my Daughter.