Children after divorce

Sir/mam my marriage was done in 2007 but after marriage there are lots of fight with me and my wife for the sake of my mother and other family member even her family member beaten me in 2008 and later on anyway my mother passed away and father too and remaining unmarried also got marry in 2010 but inspite of that the fight with me and my wife did not end any way in the result of marriage i got 2 children 1 is daughter 8 year old and son 5 year old. so i dont know but for the sake of my daughter i m pulling my life with her she hot tempered , if i abuse her then she abuse me 10 times and even she clear her hand on me usually . even her behaviour towards child not as per good mother last year when i check her not to misbehave with the children then matter spread ed too much i got beaten by my in laws even i had to get jailed for 116 and 151 due her familiy political approach sir i cant explain my situation I am geting beaten by my laws , my wife and my small children are looking so unable to understand i am worried abt the future of my children I am a poor muslim guy due to my daughter I am in confusion whether to leave my wife or not so it was story , my question is this that after leaving her may i get the children in my custody as per law or not , even i say to my wife that she may marry elsewhere and i will pay her full mehar even above but she shouted and not ready to change her nature. sir i have decided not marry but devote my life for my children betterment please advice me