Hey, @Noise I’m so sorry I was asleep when all this was happening. I know your situation is different than a lot of other situations, so I won’t push you to try meds if you’re not ready for them.
Some things I do to calm down are:
Put an ice pack on the back of your head. This will cool down your brain and reduce activity in your limbic system, where emotions happen.
Do a task with simple, clear steps. I like baking. I follow the recipe, and it’s easy enough that I don’t get frustrated, but it requires enough concentration that I don’t have room to think about other things. Cleaning also helps.
Engage your five senses. This will remind you what is real and what isn’t. Listen to soothing music. Smell something pleasant, like an essential oil. Suck on a hard candy. Look at pictures of things you enjoy. Feel something with an interesting texture, like a piece of Velcro or a stress ball.
Breathe in for four seconds, and out for eight. Slowing your breathing forces you to calm down. If you can’t manage that, breathe in for two and out for four, and slowly work your way up. See how long you can make your breaths.