For anyone thinking about getting married, I recommend the book “Men on Strike”.
Society tells us getting hitched is normal – it’s the riskiest decision you will ever make.
Fortunately I had plenty of girlfriends and worked out in advance that women are for the most part batshit crazy.
Like Sir Cliff, Badnewz is a confirmed bachelor these days!

Every woman in the world should be grateful for your sacrifice.

@ the OP

I think I’m going from denial into acceptance, and that’s painful in itself.

Go and look up the classic change curve and be realistic where you are. The phases are Denial -> Resistance -> Exploration -> Commitment

You can then pretty much split them into:

Denial + Resistance = Let Go (ie deal with the past then let it go)
Exploration + Commitment = Let Come (ie plan for the future, changed world)

What you need to remember is that you and your wife and your kids will all move through the curve at different speeds. In other words, while you may privately start getting your head around the change you want, neither she nor they may be in the same place (either behind or ahead of you in the curve).

Back to what I said before, do your prep and planning and then speak to your wife (then your kids). Don’t present anything as a fait accompli to any of them – give them time to go through the curve and get their own heads around what’s happening.

Good luck!