One strategy I use to stay calm during the day is.....

I let everything around me get fuzzy and sort of close off, like putting myself in a clear box, i can see everything but we're still seperate, i need to feel disconnected from the stressor. I don't know if that's actually healthy though lol

Breathe

sitting still somewhere and breathe or do vipassana meditation. listening to music which takes me on a different level helps me a lot too (like the sound of schiller or something similar)

Wen I'm satisfied

Going somewhere quiet, closing my eyes and taking deep breaths. Listening to music helps me as well. Sometimes happy music and then at times sad music because it reminds me that that while my life can be stressful at times.it could.be worse. Strangely, chewing gum helps me relax.

Bury myself under my blankets, tune out reality, dissipate into oblivion, escaping the pain, briefly vanishing into dreamland.

Pet my cat