Divorce vis a vis Restitution of conjunal right

My wife has been having illicit relationship with a married man for the last 2-3 years. On knowing their relationship, I once punched her hard on the face, to which FIR was lodged against me; however police didn't arrest me. We had an amicable solution with the interference and mediation of our family members. Now she is having open illicit relationship with that married man. I lodged two FIRs against that man on the charges of trespassing & adultery and he got arrested twice for the same and released on bail as soon as he got arrested on both the occasions. Now my wife has petitioned for divorce/title suit, What should I do, We have two major college going children and one minor school going. Children are with me. Our children and I are ready to forgive her and want to live together happily, But she wants divorce at any cost on my cruelty ground that I once punched her and on the ground that I am habitual drunkard. I have already left drinking 2-3 years back. Please suggest to dismiss the divorce petition and for restitution of conjugal rights.