mentally n physical harrasment by in-laws..

I am married from last 11 years but my husband cheating on me since the begining. He stole my mother's jwelery, I caught him with maid in bed, he was doing fraud n stealing money n items, he was not taking any responsibility of his daughter, my in-laws are also not supporting me. I am earing since the begining n taking care of all the expences for me n my daughter. We are not in relationship from last four years, I have cleared it to him that I will not leave this place until I will not get any security for my daughter n I am fully aware that he is living with some other woman for that I have told him that I don't have any problem if u want to start your new relationship but not at the cost of my daughter. In last few months my brother-in-law n his wife are mentally harrasing me so that I leave this place n my husband is not supporting me at all instead he had started questioning about one of my friend that whats going on between us. They are not providing the basic requirement, I have to buy every thing by my own, they try to beat me n using abusive language with me. I would like to mention that they are financially strong not weak. I accept it that I like him and I like to spend time with him because he is a very nice n mature man but we are not planned for something in future. What I would like to ask is that is it wrong to see someone else if u are not in relation with your husband from years but sharing the same house because you have a child to look after and salary is not enough so that I can move on to some other place. I spoke to my husband regarding legal seperation then he denied that he will not give me divorce until he give me security. Now a days one of my friend told me that whether my husband is living with some other woman but still I will be said wrong if I m seeing some other man because I am still living in my in-laws house. You tell me if my husband is not giving me divorce because he can't give me security n I don't have any other place to move on with my daughter so in that time period I don't have any right to see any other good person when my husband having relationship since the beginging. Am I going to get any security for my daughter if I file divorce or I will be accused for adultry....????