Need Proper Guidance To Marry A Committed Person

I'm in love with one guy and even he loves me in the same way and we want to get married but in his past he was hospitalized due some health condition, no was there to take care of him as their parents are aged people, that time his ex girlfriend helped him a lot to recover on a condition to marry him after getting out from hospital, as there was no one to support, they agreed and gave a promise to her and her family. After coming out from hospital the understanding between two was less and she started to torture him and control him bit by bit. So he maintained some distance with her. In that time i met him and accidentally we fell in love and now we want to live together. He told her the same that he is loving me and he don't want to marry her. Now she is not ready to move away and she is threatening him saying if you dont marry me ill suicide by writing whole your family names and send him to jail and if he talks to me or try to meet me she will do something to me. She is not understanding here. She is going in very rude way. Now what we can do here to get protection from her and get marriage without any problems. Please suggest.