Marriage issue

Hi my name is radhika .i got married in December 2013 it's a love marriage with both the parents concern it went well I live in USA .i stayed at my in laws place for one month for whole they used bad words to me after coming USA in June 2014 my father expired so my in laws did not allowed me to go india that I did not gave dowry but finally after pleasing my husband allowed me for my father 11 day after gng to india my mother in law call me and used a very bad words in phone since I returned to USA the day I stopped speaking to them now it's been 2 years they were using bad words to my mom and my sister Even speaking bad about me in my husbands family my sister in law lives here in USA whenever she visits my house and she call my husband she always force my husband to leave me and remarry again in 2015 July my in laws came to my house they stayed for 15 days in my house while those 15 days they fought with me everyday they agreed that they are trying to separate me from my husband always my sister in law calls in a family speaks about my personal matters and keeping all allegations on me and my character right now I'm 7 months pregant still they are doing same I have a couple of proofs that how they speak with others my husband is good if I'm happy the reason is him but my sister in law and my in laws are making my life trouble so what case can I file on them can I do it from here what does it need to file a case just for my security because when I go to India for sure they will make my life horrible as my father in law said to me that when I come to India he will file a case against me and I'm sure they will force my husband to apply divorce against me so I just want to know what action can I take so that cannot face probelms in future