How to get Divorce? Husband in USA

Hi, I am reaching out for some help. I have been married in India in 2013. After marriage I have had issues with In-Laws trying to create differnce between me and my husband. This also included harassment and mental torture. I had to go back to my maiden home for a few weeks. I thought I was able to make up the differences and went back to my husband. Subsequently, we went to USA for his deputation and stayed there from Jan 2014. However, when his parents visited in June 2015, the bad old days were back. I was put under sever harassment and mental toture; as if they wanted my existence gone from there. I tried for 4 months, and finally was forced to give up as I couln't take more. I had to come back to India to save myself. Now, I would like to get a divorce. I am in India and he is in USA. I have requested for mutual divorce, but he has disagreed to come to India in the near future. I am seeking guidance as to what are my options. What I would want is to be get a divorce in the shortest time possible, and be done with that. Hopefully, that will help me revive my current treacherous state of mind. Thanking for your avice.