Girl blackmailing for marriage

I was in a relationship with a girl but not in live in relation for 11 months. Till. 7 months everything was OK and I have told her that I will marry her but after that things didn't go good between us as she used to do things on her own and doesn't listen to me. She used to lie and doesn't listen to me. I used to Make her understand not to do these things but for some time she will listen and apologizees that she will not do again but then in couple of days she repeats the same thing. For two months I didn't meet her but used to talk in 4 5 days for few minutes. We wanted to settle out things so after two months we met and stayed in hotel to sort out things And spent some time. We slept together but didn't had intercourse. She said that she won't lie or will listen to me what I say . after that for 2 days things were good and then she started to repeat the same thing and so I decided not to stay in relation and told her I'll not marry else and she said to tell in her family that I'll not marry and I did that. Both the family knew that we will marry. From that day onwards she Started blackmailing me that she will not leave me else she will kill herself And she also has proof that we stayed in hotel. She is blackmailing on the basis of CCTV footage that we have entered in hotel. Neither her parents not me nor my parents want that we marry. She forcefully came to my house and started threatening me and my parents that she will not leave me and take the help of police to do the proceedings and get the marriage done. She doesn't listen to her parents too and even her parents has said that they have no interest in her now as she is stubborn and doing things on her own terms. They also said that they will give in written that they have no relation with her and they will banish her as she isn't listening to them. Also in her family everyone fights among themselves. So what should I do now? Kindly want your opinion