Mental Harrassement from In Laws about caste

Hi, I am from backward caste and I got married to a brahmin boy.Both the families agreed and only then we got married.Right from the beginning my father in law and brother in law are always fighting with me.My husband's brother is torturing me like hell since 2005. Below are the mentioned issues my brother in law had done: 1. He told all his relatives that I slept with him,when my husband fought with him on this issue ,he told just out of anger I told everyone like that forget it. 2. He takes money from us because he is always jobless and never returns the money. 3.Last year my husband was out of India for some months and it was pregnancy time,my father in law asked me to come home as there is no one to help.I went . My brother in law got married to the same caste girl. I don't know what happened,that girl told me because I am from a lower caste I should not touch the vessels to cook.She was moving my clothes aside with a broom because she is from a higher caste and should not touch them.I was pregnant and they never used to cook food for me.I told my father in law several times but he never bothered. My brother in law told me to go out of the house because im from a lower caste and his wife is not liking,so I left without utterin a word. 4. They never allow any relatives to call us for any functions.My brother in law keeps on raising the caste issue and harrasses me with his words. He states that he has big contacts with big people and even if I file a case no one can do anything. My husband tried his best to sort the issue but he failed and he told me to file a case against them as he is also annoyed with there behaviour.Please help me