I haven't read the other responses to this thread but I did look at all your posts just now, I will say this sounds like threads I've read 500 times before on this site.
I've read enough variations of this threa over the last 6 years to tell you he's already decided the marriage is over. He just won't admit that he's a fucker to himself or you, it's too much mental anguish. So yeah, he's rewriting history. Trying to convince both you and himself that this is what he's been driven to. God, it's so predictable, it makes me laugh.
I think it's what they call "The Script".
He's 100% checked out and decided to leave. I cannot say that his head has been turned and he has found a new partner, but I suspect so.
Either way, I hate hate hate hate reading these threads where the husband has all the power and is keeping the wife dangling, while she is trying so hard to come to terms with the bombshell, sort things out, figure things out.
What I'd do in your shoes? Tell him to fuck off and pack up tonight, and go.
Reclaim the power and take it back for yourself.
If he really wants the marriage (and he doesn't) he'll let you know. He'll come back.
I'd text this:
"Been thinking and yeah - actually, you're right. The last few years have been shit! I mean, all you do is ferry the kids around a bit here and there and think you're the perfect parent. I'm annoyed that you've left me with all the school admin and mental load over the last 6 years - I thought this was just the season we're in and I was going to push through til the kids were older but actually, it seems like you have mentally checked out and you don't want that - so I agree, let's split. Oh god, what a relief. I already do so much by myself that I'm looking forward to going 50/50! I'll actually get some time to myself now while we co-parent. I say one of us does Weds-Sat and the other gets Sun-Wed so it's fair, and we get one weekend day with the kids each. But we can figure all that out when you've moved out and got yourself sorted. Need me to pick up some boxes for you on the way home, I'm driving past Aldi? We should have done this sooner!"