Just found out my fiancé cheated on me *UPDATE*

He confessed to having sex with another woman. We have a baby on the way. My whole body feels numb and I can't sleep. What do I do.... Hurt and betrayed are understatements for what I feel right now. 
Update: I ended up forgiving him, as much as it hurt me. I wanted to move past it because he seemed so sincere about change and making himself better for our relationship. My mistake. He ended up doing it again a couple of weeks ago, but I caught him this time and officially cut him off. I realize that this is an issue that he has to fix himself, and it has nothing to do with me or my innocent baby. I will raise my little one on my own, and I hope someday he will see that I loved him unconditionally. Thank you so much for all of your comments. 💗