Beyond upset 😡😤😭

So my SO got into a little bit of trouble and is in jail. We have been together for a year and our daughter was supposed to be born next month ( we lost her in may 😢). Anyway he decides now would be a good time to admit that he cheated on me in June in my home on my couch with his son's mother! This woman has smiled in my face & i speak to her regularly because of the child they have. I want to forgive him and try to give him another chance because that's just my nature but at the same time i don't. I also want to leave him and let him deal with that while sitting in jail! 😕 i just need a little advice ladies