About a relationship.

I'm a girl from kerala. I had a relationship few months back and it lasted for 8 months only. And i decided to leave him because of my family problems and also he was not settled. By the way he was 2 years younger to me . I left him mainly because i had a very bad tragedy at home. We are 4. Dad , mom me and a younger sister who is just 14. So i had no other option so i decided to end this relation. But this guy keeps on telling me that "if you leave me..i ll write your name and suicide" and i was afraid so i stayed but i really not wanted to stay. Then i told him i cant bare this anymore and i ended. Then he keeps on harassing me through phone (sms) like "if you dont pick the call in 3 i will just viral your photos". I have all this messages with me. Finally my mom came to know about this relation and it became a huge problem and my mom requested him that not to destroy her life. "Let her live we have only 2 daughters and all". What he wants is that he doesnt want me to marry other man. He wanted to spoil that by informing all society that we had a relation. And he informs them one by one about it . He informs this through his friends. He takes the help of his friends and he sits at back silently.His friends calls major person in my locality and informs them. Once i got a call from my friend. He was like to me "i got a call from this guy and he said he had a relation with you" and i was so upset because he seriously destroys not only my life even my sisters. In kerala if people know about this i will not have a life even my family. Society is like that. What should i do? Pls find me a way.....