Hope, I'm very sorry for the pain you are experiencing.
I know the difficulty in losing your H to someone else when there is NOTHING that otherwise ties you together. I also have no shared children with my H. He however is wanting a quick D to move on with his life.
I find it interesting though what his motives are for being gone for 2yr and not pushing for D? Is this OW comfortable with the living situation that he is still tied to you like this? I wonder what he tells her to placate her that he is still M.
I don't have much real advice to offer outside telling you that you are not alone.