Ex boyfriend blackmailing me

I was living with him as I got a job in his city. And after living 10 days with him I realized that he's not the one for whom I came for, because whenever we argue he always start to torture me physically. After that I decided to leave him and I broke up from my side. As I don't know much about the city, I had to live with him for 1 month and on the other hand I keep looking for new pg and got busy in my new friend circle. At that time I got closed with one of my friend. And that was not a double dating and all... After bearing all the tortures... Then I decided to leave him... He got to know about that by stalking me and he started blackmailing me that he would tell my father and will come outside my office and make the scene... He harassed me physically by blackmailing me about my father as he know my father is a heart patient, so that's my weakest point... He molested me on his flat... And i couldn't even move my body at the time he was molesting, because he kept blackmailing me that if don't agree to that he will call my father... After that i left his flat by the help of my sister and shifted in new pg. But still he calls me and my boyfriend... Keeps threatening us about family and the company where we work... And i have all the screenshots of the messages he sent. He hit my head also and because of that it becomes a lump. I have proof of all the blackmailing sms of him where he abuses me also.. Kindly give me the solution as living like this is really suffocating and I am mentally stressed.