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

I try to ignore everything and keep myself constantly distracted by a screen. Probably not the best solution.

Listen to music. If I don't open my mouth, I don't make the mean and sarcastic comments that hurt my friends' feelings. If I'm listening to music, I don't make those comments AND I can stay calm and quietly text my best friend about what's bothering me instead.

Going for a walk with headphones on always calms me down & lifts my mood.

I try to walk and run through the park for 2 hours, until I get tired. I take a shower and pills to sleep. however I wake up at night waiting for daybreak. that's not good !

I like reading or listening to music. That usually helps for me.

Distraction. Watching shows, reading a book, taking up a new hobby.

Anything to shut the negative voice in my head.

I get nervous in public settings and I used to fret about every little screwup I made at school or in crowded areas until someone told me: Nobody is really watching you. Sure you might trip or stutter or preform badly in front of people, but(especially in a school setting) no one will care to remember by the next month or possibly the next day. Everyone is already focused on themselves and their day and their own screw ups that no one really cares to remember what you did. Sure it's a bit pessimistic but, IDK there's someting about it that makes it easier for me to forget and move on from things that used to ruin my entire year.

I try to focus on the moment that I'm in. Even if it's the middle of anxiety or pain, just focusing on that moment and not thinking about the future, because that makes it worse. I get so worked up about being a failure and disappointing my friends that I cause my fear to come true from the anxiety.

Listening to music really helps me. Especially soft, orchestral stuff like the Abzu soundtrack. Deep breathing and yoga also help. Sometimes I'll play Skyrim to distract myself when things get to be too much.

Play with my dog. Sounds lame, but she's so loving, and doesn't judge or talk so that's always a plus. Taking her on a walk is the one scenario during my day where I don't panic or overthink. It's mindless and full of love.