Calm down in English

Calm down is a widely used verb phrase meaning "to make someone or something less agitated."

Anxiety is the worst feeling ever, these last few days I been suffering badly from it and I can’t sleep. If you guys got any advice on how to calm down please let me know.

It's even worse to be told to calm down when you feel angry. In fact, being told to calm down when you're mad is like throwing fuel on top of flames. It just makes the fire worse.