Brit Please keep in mind my intent is not to be a jerk. I'm also not trivializing your decision to leave or return. I know it was VERY hard for my wife to make both decisions.
In my situation I made one thing very clear to my wife. I was not going to tolerate the relationship we had before. Since we have been living together all this time, I have practiced becoming more assertive and independent. Of course I had the benefit of being able to go at it slowly and steadily.
As for your last question, my W and myself have grown a lot in last year, and she is indeed moving in the direction of what you mention. I am happy very happy, yet I do have to admit that I do hold some resentment. I think it will pass, but some days it angers me to know how much pain we had to go through to get where we are. It is very hard to trust, because I gave her my all, once before. It just turned out to be not a flavor she wanted. Even though I'm happy I switched flavors, if that makes any sense, there is some resentment over her not accepting the original flavor. It's hard to trust, and give 100%. I imagine your H may feel like this. He's trying to protect himself. That's why he's asking for time. He may not even be too thrilled about the other woman, but it's an excuse to avoid facing the pain.
I do think you two have a chance, but it will take a very long time.