Re:advice needed JimB: Advice is nice, but there are some decisions in life that can be made only by you and you alone.
Nobody else in the world has the history with this man that you do. No one knows him better than you, and nobody knows YOU better than you.
As somebody mentioned, you hold all the cards now. Actually, you always did - we all make the choice every day, consciously or not, to stay with our mates or leave them. So take some time to figure out what YOU would need from him in order to consider getting back together.
I can understand why you wouldn't want to risk that kind of pain again, but by the same token, nothing worth having is without risk. If the end of your marriage hurt you this badly, it must have been (or at least seemed) pretty darn good.
Another thing to consider is the fact that you're in a position of strength right now, with this other man in your life. Would you feel differently if you were alone? What are your life goals, and could you achieve them better with the man you're with or by trying to reconcile?
It's really, really tough, and I don't envy you the decision. Good luck and hang in there.