I've been there--the sad thing is the marriage didn't even last a year. He wasn't physically abusive, but he was abusive in every other way possible, and he treated me like crap. I had a daughter right after we married, but he swore up and down that she isn't his. When I'd ask him questions about this female or that female or why I saw his car somewhere else other than work, he made me feel like it was my fault. He claimed that I was accusing him and that I was the one cheating. Soon after that, he had gotten another car, one that most everyone has. There was a point in time when I had felt that I had lost myself--I questioned my being; I was depressed.
All I can tell you is to stay positive and understand that you are not the reason for him doing whatever. If you have kids, you have to stay strong for them. Most importantly, you have to stay strong for yourself. You know, the Destiny's Child song, "I am a survivor" is real--whoever came up with the song had evidently went through some stuff. Just keep the faith, stay in constant prayer. Everything will work out. I'm glad that you are out of that situation; I don't wish for that to happen to anyone. People often say what they would do if their husband/man did this or did that, no one knows unless they actually experience it. What I found most successful is to be cool--play it calm, that always seemed to mess him up in the head. Now he makes it a priority to somehow let me know that he has a new girl, all I can say is I hope that she isn't as stupid as I was when I fell for him.
Just remember that the best is yet to come!!!!!!!!!