@Shalini,
It is sad that in all this, the only thing you are concerned about is how to get out of your marriage and marry your boyfriend. There is your husband, totally innocent, whose life and whose family's reputation is turned upside down by your immoral acts for absolutely no fault of his. Women like you indulge in immoral acts and then blame it all on parents, pressure, etc. If your parents are so conservative and you succumbed to their "pressure" to marry, then why were you having a pre-marital affair in the first place? Did their pressure not prompt you to be conservative too and not @#*@ around before your marriage? Blaming it on your parents is the most dastardly and despicable act that undeservedly thrusts your innocent parents in bad light too.
Don't you feel any remorse? I can imagine what your husband's family is going through. They must have had a big marriage, all relatives, friends, guests, etc. Now see what you have done! What you have committed is indeed fraud but more importantly a sin and you should admit it and pay the price for it, including voluntarily SPENDING SOME TIME IN JAIL. After doing so, ask your boyfriend is he still wants to marry you. If so, good, live happily with him ever after...
To avoid the wrath of Karma getting back at you in the future, and it surely will, I strongly recommend that you ask the Judge to put you in jail for a few weeks admitting that what you have done is unforgivable and deserves severe punishment. If the Judge is fair, he will let you scott free. Then you can move forward in your life with a free conscience. Getting legal advise to get out of your immediate predicament is a short-term solution that will continue to haunt you. Now, about your boyfriend. if he really loved you, why did he not approach your parents or even your husband before your marriage. He must be a bigtime loser. On the other hand, I commend your husband VERY HIGHLY. What he has done is just stated the facts in his petition so that society does not blame him for the divorce or entering into a false marriage. After coming to know about your dirt, he did not abuse you physically or otherwise. He just let you go. He is a thorough gentleman and I do not think that you deserve any advise to fight against such person given the background of your immoral character and selfish outlook towards life.
This forum sometimes gives undeserved sympathetic ears to some women. This is one such case. I hope that you are sentenced to at least a month in jail.