Can't restart life with my wife

Dear Sir/Madam. I got married 8 years ago (love marriage). We are living separate since more than two and half years ago. We both have a female child 2012 born. I found her being in relation with her brother in law. I found their text chat in which she expressed her interest in having a baby with him. The discussions went on few months and later i accepted. But she left our home without any issue. Exactly after 8 months i heard she gave birth to a male child. She and her parents tells i am the genetical father. But truth only she knews. How ever, i never pointed it. I came to know that she is meeting her brother in law regularly and introducing him(@ hospital, shops etc where they roam around) as father of the new born baby. Recently i have asked her divorce as i am not interested to continue my life with her. She first accepted. But then her parents involved and asking me to continue with her, which I can't do. I am ok to take either or both of kids. My parents and me can look after them well. I have proof of her texting, and she accepting her relation with him and recent photo with him. Kindly help me Kiran B