Girl blsckmailling me.

I met a girl about a year and a half. She is a divorce and I am an MCA student. Despite knowing I went ahead keeping her as my girl friend. we had physical intimacy and she asked me not to worry as she has intestine problem and that there was no chances of pregnancy. Hence I didn't use any protection. To my shock after a year she got pregnant and it so happened that the child wasn't properly hence it should be aborted. As I am just a student I wasn't prepared and her dad paid the money which I promised to pay back in some time. He was cool with it. There has been many instances where I would break up with her but eventually she would come back and we get together again. I like to have a company of friends and often we would sit for a drink and she would flirt with them on account of saying I does the same. This made me unbearably angry and I slapped and hit her. This has happened more then once. I broke up with her about a month back and she would not stop calling me now. She demanded 30000 to be paid in ten days which she didn't agree. Helpless I told her I would sell my things which she stopped me. One evening she came to me fully drunk in an auto asked Mr to come down at the street. As I came down she started beating me and attracted attention. I took her to a safe location to be cool but in vain therefore I left for home. She then went to a women police boot on a drunken state of mind and we agreed upon paying her a sum of money whatever we pagreed upon. I told her then I'll pay back in 3 months. Now she is threatening me that she would talk to my uncle. She would call up my mom she said. She got drunk and told me that she will drink a poison and die and that I would be accounted of. She keeps telling and calling me on the phone. Now she is demanding either five lakhs or talk to my mom and tell her everything. Please help me with your kind valuable suggestions.