First, the "hope" news....1/3 of filed divorces in my state are not ever completed. So even if he files, who knows what the future holds?
Second, I read your old posts. While You are very in touch with your sense of loss, please be objective about the past. Know that it's not a loss of reality but a loss of what might have been. That's painful still, I am not minimizing it. But he's been in and out of the marriage off and on from 04 on, correct? There's been an underlying inconsistency on his end. And that MUST have eaten away at the security you felt as a woman. That element in a M isn't healthy. In your future, NOT having that in your life, will be an improvement.
He's had affairs before. And He has lost jobs before, so financially speaking he was not the provider you might have hoped for either. That's not saying you are a fool or he's a loser. It's just objectively true.
However, the upside is that your life style might not be taking such a nosedive as it would if he were making a fortune or if you were losing a home you loved. I mean, it's the one "upside" of a financially insecure position. It won't get much worse, will it? And he's making some effort to be there for the D3 and to pay a bit. So far, so good.
Visit a L, get info. Knowledge is power. As long as h feels some guilt, he may be fairer with support. But don't try to keep peace for the off chance of him seeing you in a positive light; b/c 1) it won't work at all and 2) more importantly, it's at your D's expense.
Don't skimp on child support enforcement in the hopes that your h will see you more positively. I suspect the opposite, but the main point is that you do right by your D. And that's if this all goes to divorce. It may not. For now, for your sake, you must prepare for that. (Thank GOD You didn't text him to say you made it safely home..the man just told you he is filing for divorce, and you thought you should text him?? Honey please read up on Detachment and print out copies and re read them every day...literally. You must learn to do this.)
Nothing really changes as far as your DB approach, except you see a L and you keep it up! And you do NOT veer off of your DBing. You must DETACH & GAL, or lose any chance of turning this around. And if there's no chance of a turnaround, then GAL and DETACHING sooner, is better than later.
Good luck. Keep posting and start availing yourself of resources.
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016