I am trapped by a girl

i met this gal on a matrimony site we decided to become frends and know each other first and then think of marry after some days of friendship we came close and had protected s*x (this is around 1 month after we met for the 1st time ) at that time too i told the gal clearly that we are doing this own our own approvals and later on she should not blame me for this and about our marriage it will be completely dependent on our further relation and if every thing if fine in her family and mine too she said she is ok with it but the problem started after our physical relation the very next day after that she tells me that her father had left her family and that her mother has HIV+ (Before when asked about her father she just said he is not there and i dont want to discuss it ) now it is a tuff time for me as i cant introduce to her in my family because they will never accept it and more over they will dis respect me, i cant marry her because then i will have to leave my parents and live my living which is hard for me as my income is not that much... i made her understand that itz better we dont cont our relation coz it is going no where and that she should have told me this before now she is threatening me that i will complain in police and along with this she also tries to add on fraud allegations that i have played fraud with her and i demanded for dowry and i have bad character she has even abused me at time and even my family and community.. please advice me as what i should be doing in this situation she has her family member in police and will drag me in fake cases .. i cant marry her coz she played with me despite of me telling her all information correctly abt me she hided her details and now blames me for it... she has made me hate her by abusing and by threatening/ blackmailing me ...even then if i think of marrying her it would not workout due to lack of feelings and respect among each other.. she has made my life miserable and i feel guilty abt the situation my family will go through due to me....i am trapped by her and her sister in this