Can I offer some advice? I haven't read your entire sitch but I was in a very similar situation and slowly working it out.
In my opinion you engage to much conversation about D. I use to do that. When W brings up topic my answers would be short "divorce is not the path I want to take" or you already know my stance/take about D. PERIOD. Any more questions I asked her. Then I would leave the room.
I was separated for 6 months moved back and things went to crap after 1 month. It took me 6 months to get things slowly back on track and this wasn't until I did something to change the dynamic as Bond would say.
I signed up for ACOA, I go to IC, and I'm now flying out to EE to do my work.
Can you do your work? Stay out of her sandbox as 25 would say. Only discuss IMPORTANT kids stuff, limit D talks at all, force her to do all work.
I was brought into a mediators office, my W asked to date, had laptop thrown at my head on Thx giving, watched W go out to all hours, sat through months of silent treatment.
You have to change the dynamic brother. How can you do this. Of course detaching is critical. Something I still haven't mastered but getting better at.
