can't believe him

I'm posting this just to vent and get out how I'm feeling. Our relationship has been rocky from the start 2 years ago but we kept trying to make it work. While I was pregnant he cheated on me with his ex.(she emailed me asking if we were together and told me about it) If I wouldnt have been pregnant at the time I wouldn't have forgiven him and would've let him be on his way. We worked things out and things got better. They started to get rocky but when My water broke and I had our daughter who was one month early things were great. He bought a house for us. We got a home loan(so financially tied to him) to fix it up. Here we are 6 months later and he decided to text his ex (who emailed me telling me and asking me to get him to stop) this is the straw that broke the camels back. A week or two before this he had some infection with his man parts. He said if it was something serious it's cuz I was sleeping around. I did find out I had a yeast infection but nothing more.I have been nothing but faithful to him.but last night I kicked him out of my place. And  When I asked why he did it. He said he was wondering how she was. And that he didn't know why he did it. And that he had only text her that day. Which the email she sent was from the night before. So I guess she can tell the future.  It's going to be so hard to get through this. All I want to do is talk to him. But it's the same thing. He's never going to change.