I'm sorry about this development. To me, you're entering more regular DB territory. Having a H that moved out and wants to D is what most of us are dealing with. It's what most successful vets have gone through. You can have a look at the success stories at the top of my thread for inspiration.
You often react very quickly and jump to conclusions. That's ok, you're in control and the only one among us to live with the consequences. But one thing that might be helpful is to have a little more patience. When your H says "Fine, serve the papers, I'm done." it does not mean that your M is over. It means that today, your H is ok with you serving the papers and does not want to work on the M. Things can change tomorrow. Or next month.
I don't want to give you false hopes and, in fact, for the next steps, it's probably to your advantage to have as little hope as possible. This way, you'll focus on yourself and keep a cooler head through the D negotiations. But if you could avoid projecting the day's latest development in the infinite future, I think it would help you.
We're with you.
M39 D6 D3 (at S) S 2014-09 D 2016-09
"You can't start a fire sitting around, crying over a broken heart" - Bruce Springsteen.