I have one stuffed animal I'm very attached to that I hold (not in public) constantly, and that definitely helps me calm down and just chill.
I try to listen to music as loud as possible to block out other noise, and or watch something (comfort tv show or movie) to distract me from stuff when I'm overwhelmed. I'm kind of embarrassed about this, but when I'm really freaked out, I put on my laundry basket that can fit over me because I like the pressure from all sides, and it blocks out all light.
Don't know if this counts as coping, and I don't think it's especially healthy, but I often hit head against walls or hit my head/arms when I'm upset.
I like the dark and prefer to keep my lights off. If you want a tip about lighting, you can literally just sharpie over your lightbulb to tint a room a certain color
I painted my room walls dark blue but prefer to hide in my closet cus it's a smaller space. Painting takes a while, but you could probably cover your walls in aesthetically pleasing posters of your choice to make it seem less empty and un-soothing.
If you want to illuminate your room but don't like your overhead light, I think a lamp would be good investment, and there's a ton of different cool types, like some that look like glowing rocks or have customizable colors and patterns in shadow. (Could be a calming vibe, especially those that rotate slowly across the room)
_________________
MAN
"You know, I have a doctor friend I think can help you."
EDWARD
"Really? I'd like to meet him."