Can you think of the last time you told someone not to calm down, and it worked?
Or you told them to stop worrying, and they stopped worrying?
Or you told someone not to be nervous about something, and their nervousness went away?
I didn't think so.
When we try to will away negative feelings, it never works. Because we're trying to fake it.
Sure, you can try to calm down if you're upset.
But, when we try to make it all go away, most of us do it by pretending there's not a problem. And it never works. It either finds its way back out, or festers inside.
The more practical, efficient way is to acknowledge that you're pissed, angry, upset, or nervous. Give your emotions some strength to breathe.
Write about it.
Have a good old-fashioned cry.
Or you can even try one of those rage rooms that are all the rage (pun intended) these days.
(If you've never heard of a rage room, it's a place where you pay to go into a normal-looking room, like a dining room, destroy everything in sight and not get in trouble. Yeah, it's a thing.)
When you acknowledge and process emotions, that paves the way to letting them go so happier, more pleasant emotions can come through.
The bad news is, it's hard to get other people to try this.
But at least now you know that the worst thing you can say to an upset person is, "Don't be upset."