>>92030I can sorta relate. I solve this by being just a bit annoying on purpose to relieve some of that tension. Not annoying in the harassing people way, but just ranting about whatever I like or doing harmless odd stuff I felt like doing, even if it embarrasses me afterwards. People have bullied me for that, but never at cosplay events.
Sometimes you just need the confidence to be a bit annoying, to sing badly and loudly and with any luck, you'll attract another annoying person who'll sing along and meet your offer of practising secret handshakes with you with enthusiasm. I've since gained the ability to act more normally in social settings, but I don't think I'd have gotten there without cringe to cringe communication.
You just need to find someone on the same wavelength who'll enjoy your cringe in the same way you'll let them indulge theirs.