Ex-Girlfriend threatening for Police Complaint, and Compensation after cheating on me.

I was in relationship with a girl from same city whom I meet on dating site. We had multiple sexual relationship during 2 to 2nd half year long relationship. As we both were from same community, we took the relationship seriously and planned for future a bit. I never gave her promises of marriage for sexual relationship. Latter due to personal difference we grew apart and as I moved to other city when she told me that she is getting engaged. I tried to convince her that I want to be with her but didn't listen. Latter she broke the engagement, after it, she told me to she too wants to be with me. She didn't not like the guy and told me that she was forced into it. I told her to take it slow before breaking off engagement, but she did not listen and she told at home about us when I told that I don't want her to tell about us to break it. Then later we tried to work the relationship. It was on and off. I found she was lieing and hiding alot of things and I could not live with her. She disrespected me alot and said don't wana be with me then I also made the peace told her after few months after she broke her engagement. Now I got to know she was cheating and lieing on when I found snaps from her Snapchat which I logged in as knew her password. So I confronted her instead she is threatening me IPC charges, compensation of 5lac to 1cr for having sexual relationship in the name of marriage and filing a complaint for mental torture as well as call my family members to pay me back for what she is going through. I also should face the all the problems in life. What should I do. I am very tensed.