I recall reading your sitch when I first started perusing the board. Sadly, it reminded me far too much of my own (with the coming and going far too many times), and I have often wondered how you were doing since you stopped posting.
Despite the fact that your M still has not be reconciled, you do sound good. And strong.
I don't think there is any shame in being done when this seems like a pattern or a personality issue. I too have reached that point in my M and know that if this is what my H truly wants, then it is his choice. Unfortunately, in my case we have children so it affects more than just my H and I.
Do know that if this is a pattern with your H, that you are saving yourself a lot of pain. It's very hard to have a healthy marriage when the foundation of trust is constantly being threatened.
Anyway, I wish you luck and I truly hope your H wakes up one day and realizes what he has lost.