Oh my god, you poor thing. This is the ultimate blind-siding. I wrote a long post, but I'm internet ignorant, and the site logged me off, and I couldn't post what I wrote. I have a suspicion about your husband. I was wondering if he might be homosexual, bisexual, or sexually confused. Something is obviously seriously wrong with him. No one flees like this without having something they are trying to hide. He is hiding and running. One day, it will dawn on him that he NEEDS to be honest with others, and especially himself. Otherwise, he will continue to hurt many many people, and will lead a miserable life full of guilt and regret.
I want to write more, but will have to do so later. Just wanted to throw this idea out there. Yes, you mentioned the facebook girls, but that could just be a cover. Could you speak with his family to gain more clarity about what the heck is the matter with him?
I'm sincerely wishing you some peace even if it's so you can get a little rest. I know you've got to be up at night crying and wondering why......
Write him a letter, this may help you. Don't hold back your tears either. You need to release those chemicals in your bloodstream. Crying is a way to do this. (Researchers have found hormones and chemicals in tears.)