What do I do when I really want to message them?

The urge to message is strongest in the first few minutes and fades faster than you'd expect. Writing it down gets the words out of your head, which is often what you actually need. Put it in your notes, a journal, or the Unsent wall on my site, where it can sit among other people's messages and never reach them. Then set a timer for an hour. Most of the time, by the time it goes off, you won't want to send it.