When torture becomes untollerable then listen only your heart.....
Living as Liv-In relationship with any unmarried girl can't be termed as bigamy or any illegal acts until or unless your GF doesn't ditch or make an issue further.
Best strategy to follow in your case:
1. File divorce on the basis of desertion and mental cruelity if she is not ready for MCD.
2. Live with your GF but don't marry her or else if you marry also your marriage will be void.
3. If she files any false cases of 498A or DVA then it will not sustain too longer for her as it will fall apart soon if you have guts to tolerate the initial hi-cups and even not bother about to go for a forced vaccation inside the jail for days or few months maximum.
4. In India Men are treated as only sperm donor and nothing else so don't expect much from anybody.
5. Earn much and stay happy as nothing is going to force you to live with your wicked wife.
6. If your wife is a greedy leacher then both you and your GF gather your freedom amount and pay your current wife to part away amicably with her.
7. Always make a note in India crime is purchased but only the right price to be given.So,you haven't done any heinious crime or a national/International crime that you are worried about your life.
8. Just chilled out man as you are not only the single person who is facing the same scenario.
9. If contested divorce goes on and MCD options doesn't work then don't worry within few years she will come to you for negotiations.
10. Till then enjoy the ride of Bad Laws and once you get freed from such trap you are free to announce your GF as wife or whoever at that time.