Mental Torture From Ex-Girlfriend

I've created a matrimony profile and a girl gave me a request. I accepted but I didn't contact her further. She found my profile on Facebook and texted me but I told her I was about to uninstall the app and not in the idea of marriage for a further 3 years. But she told us we can be friends and the relationship ended in love. She was talking maturely and seemed to be a nice girl. We went out twice and we took a few selfie pictures and I made a promise to her that I will not cheat her and will marry her. But later I found that she was lying many things and her character was not good. I told her that we'll break up. But she was blackmailing me that she will commit suicide. I took this matter to her family but they also supporting her and blaming me that I cheated her. Now she knows my address and blackmailing me that she'll come to my home and will make trouble. Also now she's using abusive words on me and my family and kept on disturbing in many ways. I have voice notes and chat of it