Hey KLB, sorry to see you here, but our sitches have a lot in common. I actually told H to leave because he wasnt happy and said he didn't love me. We have been in a LDM (long distance marriage) for the past four years though, with him only home on weekends. He said he was done, but I said I wanted to try. Recently found out he had been lying and has been seeing someone for "a couple of weeks". But like you, I wonder how long, since there were changes before he "left".
But other than those differences, my emotional state and ML status are the same as yours and I am sure H did not feel attractive or loved or valued.
I was doing very well until I found out about OW and must say that threw me. For me it is the lying, because I don't lie.
Anyway, keep up the DBing and look at everyone's advice and sitches, they are helpful. You are still civil, so that is good
Don't bring up R and find something fun (IE GAL) to do.