idk what to do..

So I'm 5 months pregnant and my bf has been getting on Craig's list and looking up women to fuck. I confronted him about he said oh those were old which I knew they weren't and told him I knew they weren't he finally admitted it..well then he paid over 300$ for live cam porn and I found out about it..then last night I found out about him making a porn account on a website and before he could even explain himself I told him I'm leaving now he's all mad saying he didn't do anything. How am I supposed to trust someone who keeps lying to me.