Headphones, sunglasses & avoiding being bumped go a long way in helping the world get too overwhelming to begin with, as well as finding soothing sensory stimulus that helps the brain feel less jangly.
Water running or rain sounds, blowing bubbles, a stuffed animal with excellently textured fur, rain or glitter sticks can all be soothing & even slightly annoying textures like nail files can help make the crappy sound/texture stop replaying on an endless loop of repulsion. (I can't even think about a mister clean magic eraser, ugh!) Weirdly enough, the right kind of loud music helps too.
It's not all bad though! I believe I have this & am working on getting a diagnosis. The same areas negatively over-stimulated can also bring intense pleasure when positively stimulated & those too can be replayed by the brain.
ASMR videos can make excellent exposure therapy tools & some of them feel SO good on the brain.
Thanks for a great read, it's lovely to see awareness about this going out. I wish I'd known sooner & avoided a life as a lonely recluse.