I mean this frankly, not to be mean, you may not have been "so close".
I would go back to not contacting her, especially since it seems like no kids are involved. It seems like she has some interest, or else she wouldn't talk your ear off for 4 hours. But she isn't ready to come back as you found out a couple days after your "date". I would take the mindset of you want your lady to want you, and if not then see ya later. Now I know this is hard bc it's your wife right? But she apparently doesn't think that title matters right now.
When she BD'd you, did she say she wanted a divorce?
And how do you know she still talks to OM? Snooping? I'd quit that. It sounds like you need some GAL to fill your days out and keep yourself occupied.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.