I wants to get seperated from my wife with mutual consent or through court.

I am a physically challenged person and my wife is absulately normal lady. My age is 54 yrs. and her age is 41 yrs. When we enquire about the age of his daugher he told she is 19 yrs. but we came to know after several years that she was only 17 yrs. old at the time of marriage in Dec.1996. Wheter this marriage is valid. My wife and her family members are abusing me and also extracted money from me many times. Since she was liking some other person in their relations but he was employed and that is why she married with me. I am having 2 children (21 yrs daughter and 19 yrs. son). Last few year she refused for my conjugal right. She alway talk to me in insulting laguage. Many time she left the house for 20-30 days and stayed with her parents. During these period being a physically challange person I have taken my children responsibilities like making food, washing clothes and utensils, etc. In 1999 I filed a case for divorce in family court but some elder people from our family made patch-up and I withdrawn the case. Today also she left the house. Now I have decided to get divorce and leave peaceful life. Please advice whether her marriage in the age of 16-17 is valid today and how much maintenance I have to pay her. My net income is Rs.40000/- pm. With regards. - Avinash