I have told him as much and he has said 'I am here aint I', but what I am missing is the commitment and remorse for his actions. That is what is missing.
And it will stay missing, maybe forever. While he is still emotionally attached to someone else, he is incapable of feeling any remorse. I told my W much the same thing and her answer was, "I can't be sorry for something I haven't done." Yeah, well, BS. But it's true, in their minds, they have convinced themselves they have done nothing wrong.
Don't let not hearing 'I'm sorry' stop you from letting him go and becoming a better person. Do it for yourself and not for him. One person can change a M, but you do that by changing yourself for you and not for him. If he is strong enough to realize what he's doing is wrong and he notices you not putting up with his chit anymore, how happy you are and how great you look, he will have the chance to win YOU back, not the other way around.