Its very imp... suggestions plz?

i was married to a girl without knowing to any of our parents and the same was solemonized and registered at register office. i got the certificate and we lived seperate since it will take time for our parents to accept our love. but, in between, we got some prob and we are seperate now. i got all the proof that the marriage was with her will when it happened ( msg , conversation, photos etc.. ) she is engaged now to a different person.she has totally hidden all these to him. we did not apply for any divorce and still she is my legal wife. what to do legally ? is there any way that she can deny our marriage ? will she be able to ask for any compensation , during divorce case? i have sent her a legal notice asking her opinion.. what to do if she commits suicide since it will cause her family a bad image ? is there any chance i could be arrested?