When you've carried it another month
It'll happen. You'll read this book, agree with it, choose the listener, and not send the message. A month later the worry will still be in the drawer and there'll be a second worry, which is that you've read a book about it and done nothing.
A month isn't a life. What's happened is that the burden belief is old and the book is new, and the belief got the month. The worry is a month older and so are you, and the message is exactly as sendable as it was.
Tell late. The telling works after a month as well as after a week. It works after a year. The only thing that changes is that "I've been carrying this for a month" becomes part of what you say, and that's a sentence the listener will understand, because most people have carried something for a month.
Work out which belief got through. Was it "they've got enough on"? Then chapter 3, and remember who you'd want to be told by. Was it the first sentence? Then chapter 14, and write it as a text. Was it the fear of being the one with a problem? Then chapter 12, and notice that a month of "fine" is closer to that than one telling would be.
No streaks. Don't count worries carried alone as failures against a rule. Count tellings. The first one is the one that matters, and it doesn't matter when it happens, as long as it does.
One more thing about the month. It's had a cost, and the cost is the point of this book, but it's also had a use, which is that you now know what carrying it feels like from inside, in a way you'd have forgotten if you'd told someone in the first week. Use that. When the next worry arrives and the burden belief says "they've enough on", you'll know what the alternative is, because you've just lived a month of it.
And send the message tonight. Not because the book says so, but because the worry is a month older and the drawer hasn't helped.