I think the fact you have realised your mistakes is a good start, however I still think you have a long way to go. I see your actions as immaturity, I don't mean that in a nasty way but the thoughts of wanting to go back to life before commitments, the lying and sleeping around, just screams at me that you weren't mature enough to deal with your actions. I think it's a normal 'feeling' for guys to sort of become frightened especially pending the birth of their 1st child and have thoughts of fleeing to avoid the responsibility. But to act on it is another thing altogether.
I think the best thing you can do now is prove yourself, be a loving, commited father. Be a support to your wife, be HONEST. When somebodies trust is broken it can take a long time to be mended and the only way that is going to be mended is for her to see you're serious and commited, no backing out, no lies and then she might consider taking you back and becoming a family again.
If you're serious about wanting your family back then I can see it working but you said before you kept changing your mind, doing that is just hurting her more and it will only make things worse, not better. Goodluck