My DH doesn't isn't usually very introspective but has given me the best piece of advice anyone has ever offered up.
You cannot change a person, they can only change themselves
Going over and over this actions will only pull your self esteem down further. Simple plain truth is - he did it because he wanted to, and it was more important to him than you. I'm sorry if it sounds harsh, and it is in no way a reflection of you - his choice, his actions, his consequences.
There was nothing you could do to stop it- selfishness runs through this joke of a man like a seam of coal (except with no use/value!)
His life seems to be spending all day, every day in online chat rooms (and I guess wanking), he has never had any friends (does not seem interested) and does not see his family.
Chatting online is safe, no one has to know how sexually and socially incompetent he is, its a safety net of fantasy where he is the alpha-male stud muffin with loads of interesting things to say. In RL you know that not to be true, in fact he is a sad little man hiding behind his keyboard grabbing his own balls instead of grabbing his own real life by the bollocks.
Plenty of men out there who don't have the emotional spectrum of an earthworm and the personality of a damp towel.
If posting makes you feel better, then keep getting it out. Think of him like a bad case of nits, it may take a few combs and a few chemicals wine
but once your head is clear that little itch which was bugging you will be a long distant memory.