If the marriage is not working or is over, I don't think it's a defeat. I think it was right at the time and HP has other good experiences in store for you. It's a Western Culture fallacy that marriage is forever, that there is only one person on the entire planet meant for us. It's a good story, but not based in reality.
You have children with your H, correct? Maybe you two were "meant" to come together because those precious children were meant to be born. Maybe you were "meant" to be together because you needed this relationship, this experience for your own personal growth. We can't know the reasons until HP wants to reveal those reasons.
As for the ring, perhaps you could have it reset as a new symbol of a love that led you to you. And moving forward does not have to preclude never having room in your life for him ever. It just may be better that you don't have room for him now.
Hope you feel better!!!