Advice on the affair my wife had

Well as the title says, my wife had an affair with her co-worker off and on for over 12 years, longer than half our marriage. She introduced him and his wife to our family, our children all became friends and we celebrated many occasions together, as well as vacationing together many times. She had unprotected sex with him before and during the pregnancy with our daughter (I did a paternity test, she's mine). We will have been married 20 years this year and we've been together for over 27. I talked to a priest about getting an annulment, but he thinks it's very unlikely. She has a pattern of mental abuse with me as well withholding intimacy for years. As far as everyone knew she was a picture perfect Catholic throughout that whole time. I'm trying to reconcile with her and to her credit she is as well, but what if 3 can't ever get l accept it, what if I can't ever truly forgive her? I'm now forever married to my abuser and the person I trust the least in this world. What am I supposed to do? If I have to stay married to her, I will and I won't remarry, but she will not be living with our children and me. I guess I'm just asking for input and advice on how to proceed with this.