TJT, I'm so sorry you're facing this. I don't have any words of wisdom on your particular situation in this moment, but a few things I'd like to point out.
You're really doing well in handling this. You are so aware of the "why"s you are upset - very logical, very self-aware. No irrational anger, you can pinpoint exactly why you are frustrated and hurt. Don't discount this, because it is very difficult to think clearly when dealing with an emotional crisis. Your last sentence, "it's not just going to go away" and yet you understand you can't hide under a rock and ignore this - this is all really great. So please know you're doing a good job in a ____ situation.
I guess what I would say regarding the email is to be aware of your tone. You don't want to sound too short and dismissive, but you don't want to be fake-happy. You want to sound competent, and that the ball is in his court. Think "brief", but not "curt". Along the lines of, "You can find the info we talked about attached...." and maybe a sentence or two if anything needs logistical explanation.
He knows what he did, and he knows he asked to proceed. So the fact that you filed, in my opinion, does not have any impact on where this ends. He was reaching out to say that he was moving forward. This was not a temp check, this was him proceeding. I don't think in this moment there is any action you can take to stop this. It will have to all come from him.
Remember, he knows you don't want this. I know you're desperate to throw a hail mary pass, but I don't think you're in a space where it would do anything. Aside from being the first to fill out the forms, I think you can safely sit back and not prompt any additional steps from here on out. He will do what he will do.
Some people need to complete their process before realizing their mistake. Let him complete his process. In the meantime, you're doing work on your own process. Yours will be more fulfilling.
