threat by hus

Good after... My name is vani. I am hyd resident and Hubby is from andhra. Ours is love marriage.its been four years. We dont have kids yet.My husband is a cancer patient. Knowingly I married him though my parents were not happy with my desicion. After marriage I came to know about my husbands affairs with other gals. Faced marny problems not only with my hubby, with my MIL but also with my SIL's. All started torchering me mentally about my caste and also dowry. As my hubby is from higher caste,this is being major problem now a days between us. He is abusing me taking my caste name as I'm from low caste. I feel like dying. It wasn't any problem before marriage but now hearing to other friends and relatives my hubby started becoming greedy about money(dowry). Used to booz and beat MIL used to encourage him for fact my MIL &SIL also beat me twice. During marriage my hubby used to earn just 7000 but know he is earning good. And his circle increased with some well known people. Now he being repent for marrying me as he would get a good gal with gud money. Yet we don't have any own house.. He don't have any properties too. He do finance in the market. No we r staying in a rent house. Now my husband have an affair with my owner's daughter. I came to know recently. Something is cooking behind which I am unable to understand but my husband is trying to get rid of me now. Asking me to leave him and divorce him which I'm not interested. I came from a very good family. If I take any step my family will suffer. Just thinking that,I even tried to commit suicide as well. I doubt that my hubby is planning to marry my owner daughter as I divorce him. I am unable to hate my hubby inspite of everything, as he is my first and last love of my life. If I have to file a case regarding this where I don't want to give divorce and want my hubby back. Please help me. As I'm feeling so helpless.