Divorce against contest within 2months of marriage

My husband and I met through parents, fell in love and decided to marry. We had an amazing 2months courtship. My in laws and husband didn't give me even a slight hint of their intentions. Soon after marriage we went for our honeymoon. I had his phone with me and saw romantic messages of a girl and his response too. I kept quite for a month and kept reading the messages daily. After we returned he forcefully sent me to my parents for 10 days and during these days he went and stayed with his girlfriend at a hotel. After I returned I saw thier chats and bookings and confronted his parents. After which his parents and sister started torturing me mentally and physically and supported his relationship with his girlfriend. They both were suppose to get married but coz she is from a poor family boys parents didn't agree. They have kept all my jewellery, car and artifacts given during the wedding and sent me to my parents place. After doing my own investigation I found out that they already have an affair since 4years and even during out courtship,he had been with her. I am suspecting that he married me only for dowry and planned with his girlfriend to harrass me soon after marriage, so that I leave him and he gets all my jewellery and money and his parents will allow him to marry this girl. How can I proceed with this case? I have stayed with my in laws only for 15 days and they tortured me a lot.