Hope, one tiny word of warning. It's about your last sentence.
"I wish I had that "his loss" feeling. And honestly I wish he did too."
I know that feeling well. But don't wrap your head in knots with what you assume he is or isn't feeling. You do have clues, and know how to read him probably better than anyone else. I get that. But you only have to review Blu's story to know that we don't actually know what the WAS is thinking during these times. The either A) Absence of emotion or B) Abundance of emotion makes it very difficult to read them in any "normal" way that we are used to.
I don't care if a relationship splits because of MLC, because of an affair, because it was just the "right thing" to do - it's major for ANY relationship to be on the rocks. And he is feeling something in his own way - but it's not his normal thought process because this is not a normal situation. So you can't read him like you maybe always have.
When I stopped guessing what my WAS was thinking I was able to let go just a bit more. I was able to shrug my shoulders and just say, "You know? I don't know what she's thinking. I only know how I feel and what I'm thinking". And that really helps reframe things. It stops the cycling to a certain degree, and I find it a good practice to constantly remind oneself of this fact.
