Blackmail by my exgirlfriend making a rape charge on me

Last 2 year back, a girl and her mother came at my home and asking me for tuition in her subject. I refused to her but when her mother pressurized i told that i will only help in her subject since im a teacher and their family reside in our colony. so i helped her in her subject appoximately 1and half month. During teahing i feel she is moony and seeing me on other way. so i asked why you look moony. she told me that she had a relationship with a boy appoximately 4 year old, and she had physical relation with that boy. and her mother knew that.I advice her to see her carrier. But after this conversation day by day i feel she graze me more than before. and trying to impress me by her makeup, clothes and the way she graze me. i ignored all these thing.one day she hug me and kiss me and said that she like me. i told her that u know i m married. but she told she like me. since she came my home daily so she understand there is some problem with me and my wife relation. one day she asked me the relation of my wife with me. i told her in marriage there is always initial problem for adjustment. she again told me that she loved me. but i refused her love and said u can be only friend. After 1 and half month she got busy her exam and i busy in my job. but she came after every 15 days for several excuses, like filling job form, or her other works. Initially i was irritating she came my home without any serious work but after meeting with her several time and her perposal i feel attraction toward her and starts automatically liking her. she told me to call regular her at that time when she is going outside. during after 3 month relationship i feel she is playing with my emotions, during this period i had not made any physical relation with her. I told her to break all the thing. after 1 and half month after she call me that she is sorry for all the previous thing and want to relation with me. after that she started call me regularly. our relationship again bound. during last 9 month relationship. last month we had made physical relation in a hotel with her consent. she is not a virgin( by two finger test by me) girl, but she bleed alot (not understoodable by me, even i teach biology). so i admitted her in a hospital. she and me both are in fear because society and her family and my family will not understand our relation. when her family knew all this thing they made pressure on me to marry her( but i already understooded they are not interested in marry they want money). so i told them i m married and i had a child. the girl also try to pressurized me to marry with her, or else she will file a rape case on me and abusing me. since im a govt. servant. so i told again it is not possible me without divorce i cant marriage and this marriage is nill according to law. but she and her family are not convinced. after 4 days of all these thing that girl had gone to police station and give a complaint of rape case ( even she admitted orally in front of sub inspector that it is her consent for physical relationship). they made a lot of pressure on me by making fear of firing of my job, rape charges, and add the name of my younger brother in fir. so i told to do all the thing whatever they said. during this drama her mother first demand 6 lakh, later 10 lakh then 15 lakh and her daughter demanded 50 lakh. i told them to put me jail i dont have 15 lakh or 50 lakh. my salary is small. after making lot of pressure on me and see it is harldy for this person to get huge amount they got agreed on 8 lakh for which they had taken forcefully 4 cheque for differnt dates of month. in my account i have no money. and no bank is giving me 8 lakh as loan. so plz give me suggestion what should i do. plz help me.