The next ask
There are three things to do, and the first one can be done today.
Make one small request of one safe person. Pick something that barely matters, so that a no would cost you nothing. Borrow a drill. Ask a colleague to read a paragraph. Ask whoever you live with to make the tea. The point is to go through the swerve once with your eyes open, say the sentence, and see what comes back. Then compare it with what you predicted.
Tell one person about the pattern. "I'm bad at asking for help. If you see me struggling on with something, say so." This does two jobs. It gives someone permission to offer, which many people hold back from doing because you've always seemed fine. And it's practice, because telling them is a small request in itself.
Write one plan in the form from chapter 10. "When I notice I've been stuck for half an hour, I'll message someone before I try again." Make it fit the place where your habit costs you most, whether that's work, the house, or the conversations where you say "fine".
You'll swerve again, probably this week. When you notice, make the late ask if there's still time, and move on.
You're going to carry on being capable. Nobody's asking you to stop. But somewhere in the next few days you'll be halfway up a ladder with nobody holding it, and there'll be someone in the next room. Ask them.