Worried for pre-wedding false case or use goons to threaten the family

Hi I'm residing in New Delhi n wrking in an MNC in noida. I gt engaged to a grl in March. Her and my family were known to each other through my elder brther in law. She came to delhi abt 2.5 yrs back and contacted me fr a job. Since then we became frnds bcoz I helpd her in gttin a job, pg in Gurgaon etc. We strted talking 2 ech othr n thn she prposed me. In d beginning i denied that we r just frnds and nthing mr thn that but hr continuous effort made me fall fr hr and we startd meetin like a bf and gf. Later on she askd me for marriage but I denied that we are not that much compatible for each othr. But hr continuous approach made me fall for hr and i also thought to give a go ahead for this. So last year in May I was with her and i don't know what made me think that i checked her phone and found that she was talking to a guy regarding marriage n convincing him that she has started feelin something for him. I felt bad and took the chat history to my mail and next day read it n told her about her lies. She accepted it and said that yes i talked bcoz u were not ready for marriage but as u r now then i'll stop talking and said sorry for multiple days. I also thought that what's wrong if she is looking for secured married life. Then i told her to inform about it to parents and we'll go further for it. Our families strted talking on these things, few things were gtting discssed tht from where will we hv to do marriage n all. In btw she has informed me that her parents are talking to another guy as well but she is not interested and she also asked me not to talk to any girl if my family is getting contacted by any other girls family. I thought that the girl is very mch sure abt me and wants me only. Few days later i came to know that she had someone in her past as bf and she was still talking to him. When i said this to her then she said nothing is thr in btw them she is just talking like a frnd. Still i told her multiple times n tried to make her understand that she should stop it bcoz she will ruin her own life. Then at 1 day i got irritated and called tht guy n he said we are still like a bf and gf and i come to Delhi very often n meet her and have gone for a outing as well. I got stunned and was unable to understand that what's going on. Then i called the another guy for whom she had said that her family is talking about marriage and thay guy said yess the girl talks to me and says that she loves me. I found everything wrng n calld hr n said that i won't marry bt she started crying which made me feel bad. Due to word limits i m mking in short tht aftr so mny issues i accepted her n got engaged in march but then i came to know that she had physical with her bf too n had done it with me also before engagement. I had asked her before if she had this with her bf or not she said no but later i got the truth n still she lies to me. So i denied fr Marriage. Her family is rigid n not accptng her fault n sayng that we won't keep quiet n I'll hv to marry.