The decision
You've got the argument and the method. What's left is to decide, and I'd like the decision to fit in one sentence.
When I've carried a worry for more than a week, I tell one person, in one sitting, and I let them help.
Three parts.
The first is the week. A week is long enough to know the worry isn't passing and short enough that it hasn't filled the room. If you've carried it longer than that already, the week is up.
The second is the telling. One person, chosen as chapter 20 says. The sentence, the thing, all of it, the request, as chapter 21 says.
The third is the help. Accept it, follow it up, take the step, tell the co-owner.
There's a form of planning that helps with rules like this, and it's been tested many times. Peter Gollwitzer and Paschal Sheeran reviewed ninety-four studies of it in 2006. You decide in advance what you'll do and when, in the form "when this happens, I'll do that", and people who plan that way follow through much more often than people who only hold the intention. So write three.
When I notice I've been carrying something for a week, I'll write it in one sentence and name the person I'll tell.
When I've named the person, I'll send them "I've been carrying something and I'd like to tell you about it, can we find an hour this week?" the same day.
When they ask what I need, I'll say one specific thing, and when they offer it, I'll say yes.
What to expect. This is my expectation and not a finding. The message will be the hardest part, and you'll draft it three times and send it on the fourth, and the reply will come within an hour and be some form of "of course". The hour itself will be shorter and less awful than the month you've spent imagining it. There'll be ten seconds after the opening sentence that feel very long, and then a question, and then you'll be in it. Somewhere in the middle you'll say the part you were most ashamed of and watch their face not do what you'd predicted. Afterwards, the same evening, the worry will be exactly as real and noticeably smaller, and you'll sleep better than you have in a month, not because anything's been fixed but because you're no longer the only one who knows. In the following days the wander will come less often, and when it comes it'll have edges. And the person you told will treat you, from then on, as someone who trusts them, which is what you'll have become.