Hi, I have just caught up with your story. And I want to share something....
My H was sleeping around while I was pregnant. And continued to do so after the baby came home. I was absolutely clueless stupid stupid stupid. He wasn't having an affair - just lots of sex with different women that was not me.
That baby just turned 10 a month ago, we had two more after that.
My sitch wasn't as bad - my H begged me to stay. He was so remorseful, blah blah blah. I was SHOCKED beyond belief. He was my Knight in shining armor. Duh Duh Duh.
Well - we did stay together and I do not regret it at all. My H had serious issues - that were not apparent to me. He was seriously immature in some ways and got his ego fed and fed and fed by his ability to get other women in bed. Whenever he felt inferior, or like he couldn't handle this grown up life (and expectations) he went for a roll in the hay. Like once every six months or so. (for like 3 years).
He got some counseling - then got some really good counseling - and he is a grown up now. He does not cheat anymore and I honestly believe he has not since the day I found out. (Baby was 8 months old). He honestly just could not handle it. He did not have the tools to deal with it all. When we got married we bought a house and were trying to be adults.
I know now that it had absolutely NOTHING to do with me. He didn't know how to make himself feel capable and important so he let stupid girls do it for him.
Here's my one warning though. I am hanging out at these boards because H told me recently "he doesn't have any more to give". etc etc etc. One big problem we have had - until only very recently - is that I never really forgave him. I said I did. I wanted to. I believed he no longer acted that way. But I just could not get over the fact that he didn't love me enough not to do that.
Again - it had absolutely nothing to do with me and how much he loved me. He had low self-esteem that he built up by cheating. (His parents were always pretty shitty to him - I think he's relied on girls to make him feel good since he was 12).
Anyway. I am really sorry that you are living through this. I don't know what will happen, but I wish you all the luck in the world. Just remember remember remember that this is NOT your fault. He needs to grow up.