I can't tell you how much of that rings true, it's such a comfort to hear! I'm the same with restaurants/bars and I can usually be found in the smoking area of a nightclub! Hand dryers and hair dryers are my biggest enemy. The only way I've ever found to explain it to my friends was that the noise makes me feel claustrophobic and like everything is weighed and pushing down on me.
When I was first diagnosed I was given no information on it, just that there was no cure. Only recently have I fully understood the impact it has on my life and my other senses. Like you I was diagnosed with social anxiety. After seeing another doctor recently they believe I have associated the feelings of anxiety I feel when I'm in restaurants or cafes or loud environments to being out and around people. I bought some earplugs a little while ago, and like you said the difference is incomprehensible.
I'm lucky that my spd doesn't affect my touch as severely as audio affects me. I struggle to touch certain fabrics without getting that claustrophobic feel, such as velvet and wool. And my friends no that under no circumstances are they allowed to touch my face or touch me in general especially if it's unexpected. My face is very sensitive to stimulation especially heat and water. I can't put my face under my shower if it's so much as warm water and I have to build up a lot of courage to put in in cold. That's really the extent of my touch stimulation. I could go on for hours about audio and taste but you've summed a lot of it up in your reply.

Can I ask, what's a sensory deprivation tub?
Do you feel your spd has got worse as you've gotten older? That's one of my biggest fears, I struggle so much already.

Thank you so much for taking the time to reply!!