Divorce or get rid to my adulterous wife or any other way to separate

I had married 3 yrs before and after that I found my wife in adultery with some one and her I contact her mother and told every thing then she promise this will never happen again I have joint photographs of my wife in kissing position But now she has no fear of any one and staying away from me from last 13 months and she has a job in hospital reception . and she is not agree to give divorce and I am hesitating to take step because of pressure which will remain on me for interim maintenance bcoz I have no sufficient source of income what should I do to resolve it with out hurting my self please help me ........ She tells lie to her parents that I abuse and beat her so her mother is thinking that her daughter is correct even after knowing her adultery and says that it is of before marriage to hide the facts