I so very much know where you're coming from. I have felt all the same gamut of feelings regarding my M, and who my xW was, for 16 years. I was the luckiest man on earth, or so it seemed.
I don't think I can reconcile the person now with the woman I married, not entirely.
And I too have about come to the conclusion that I don't think it likely I will find another life partner. I feel a strong intuition that I gave my best effort and gave my whole heart to one person, and because of that I won't really be able to top that. I take M too seriously, I guess, especially now.