matrimonial case

Hello sir/madam Its been almost one year of my marriage and certain things came out when i went to my in law's house and these things has ruined my marriage. My partner and his family members are trying to make my life worst by demanding dowry and torturing me for almost each and every thing . After marriage i came to know that my husband has extra marital affairs and every in law was supporting him to carry that affair and leaving me behind . My mother in law and sister in law are creating continuous problems in our personal relationship as well by misguiding him. They tried to take my life as well . They are not feared about divorce kind of a thing and they say that divorce is a trend of today . When my elders talked to them they are demanding a written document stating that they will not be responsible if anything happens to me. Now my family members are not ready to proceed in this way . Kindly suggest me how to proceed legal procedures and if i go first for the divorce then will it be in my favour or not ?