Husband's harassment

My husband is alcoholic for more than 40 year . after death fo his first wife by drowning in pond with her new born child in suspicious condition,we got married in 1976. he is a central govt. employee of railway. he left me in his house with a girl child in bihar and went for his job in WB. for four year he dont contact me but he have secratly contact with his family(my inlaws) which I come to know by old letter exchange between them , those letter are in my hand.In 1981 he brought me with him and never allowed me to had contect with my relative for 6 year . After haveing two more child we went to my inlaws house then I come to know that he hadbeen always complent about to not being a good wife and steeling his mony. I try to adjust with them for shake of our children. his behaviour towards me is never good . now my two daughter had got married in Kolkata and we also have a house. but now he compeling me to leave kolkata and go with him his village forever. throught our whole married life he was never careing toward our children. he always spent littel amount of money on family and alots of in his alcohol. now he disclose how they haresst his former wife and provoked her to suicied and if I dont obey him then I will have same result. PLEASE HELP ME