You can't control what your H thinks about your actions or what a post divorce R will look like. The only post divorce R you need to worry about is that of a co-parent.
Mystik - NOBODY wants to get divorced. Sometimes though it has to be the next step.
You are allowing feelings to dictate your actions. The facts are your H left you, has cheated on you more than once, treated you poorly before you married, is living with OW and preparing for the arrival of a new child with her. Nothing in that summary indicates anything other than his desire to dissolve the marriage you have. It hurts but it's fact.
Your H will NOT suddenly change his mind or come over and drop to his knees acknowledging your hurt. He is too invested in this other life and quite frankly has been kicking you around for years. You are worth more but until YOU decide you are worth more your life will remain terribly, terribly painful.
You are doing nothing different than you have always done - you have always waited around, tolerated his BS/cruelty/infidelity and gave him the green light to act however he wanted. If he ever does even think about coming back (doubtful IMO) things would end the same as you are not doing anything different.
Rebuilding your life is NOT easy. But you can't keep saying "I can't". If you are cool with letting one "man" dictate the rest of your life there isn't much we can do about it.
The closer it gets to the baby being born the more aggressive your H is going to become. Read all the stories here - the more invested the wayward spouse becomes in an affair the more they push for the divorce.
Forget shocking the hell out of your H - shock the hell out of yourself and say NO MORE.