Inlaws are keeping husband and wife separate and causing conflict

Me and myhusband were happily married and staying in the US post our marriage for six years without any problems. However, on the insistence of his parents, he decided to relocate to India to stay with his parents. Six months before coming to India, his parents decided to visit the US and stay with me and my husband. During that time, my m-i-l used to regularly brainwash her husband against me and taunting me, and it went to such an extent that he started hating me. I was hoping he will change his attitude so I didn't say anything and continued to live with them. After we returned to India, I went with my husband to stay with my in-laws at their place. However, I was treated very badly and mentally tortured daily. There was no privacy between me and my husband; and my husband was totally influenced by his mother and never supported me. I tried staying there for 2-3 months but it didn't work out due to the constant mental harassment. Eventually, I moved back to my parents' place and have been staying with them for over a year. In this duration, I have had very little communication between ourselves. About 3 months back, we met again in another city and agreed and decided to stay in a different city away from his parents. My parents also went to his place as a courtesy visit after our discussion in order to smoothen things out. They also agreed that we both must live together and they would not influence his decision. However, as soon as he went back home, he reverted his decision and asked me to return back to his place and that he won't move anywhere. He has now sent a legal notice asking me to return to his place. I want to give the marriage a chance and try and sort out the matter. Please advice what should be my future course of action.