Does him retiring change your life in any type of way other than the resenting him?
You've raised all your children this far, if he hasn't contributed so far and you don't expect him to in the future, then I don't get it.
He's only going to be more available from here on out, but you seem like you don't want that at this stage ?
Is money gonna be an issue?
You've smashed it all out so far, no point holding a grudge for the final 5 years tbf. He can either do it, or you can continue
But don't worry too much - raising your children, being there, showing up for all the events and thinking they are still going to call you for help is an absolute fucking blessing tbh. You aren't losing out here, you've already done it all my love.
Let go of the stuff you can't control and go with it, do not let the bitterness eat you up, he can take alot more on from now than you think. Not just school stuff but also life admin, the shopping, cooking, and you can take some time for yourself too, you will have a better quality of life from him retiring and the kids growing, I'm sure. Don't let what could have been stop you from appreciating what now is.