I have a fidget spinner ring that’s kinda discreet so I can stim. Maybe you can get some loop earplugs to dampen the noise. I also used to bring this tincture and put a few droppers full into water and drink that. Kava is in it and that specifically can soothe your nerves and is known to help people loosen up/be more sociable, but you don’t get drunk or high, it’s just an herbal tincture. Its a very…strong taste though lol. Or maybe, it could help if you could find a bar arcade, play pool, or do some kind of activity while out with them at the bar. being able to focus on a game or task might help everything else to feel less intense.
Also, there is nothing wrong with just going for a short time and leaving when you know you’re at your max!
Experiencing one symptom of autism does not make you autistic.
I’d suggest exploring Embrace Autism and take some of the tests if you suspect that you might be. That would be a good jumping off point.