Is there some “severe dysautonomia” I can put on myself to not suffer in public places?

Basically, there are two things I struggle with.

First, is when I go the pharmacy/shop/bank/wherever and ever need a chair to sit and wait, ever not to wait 30 mins bc all this time a single person is chatting with a seller/bank employee. 90% of times I ask to let me go ahead bc I need 1 minute to pick up pre-ordered medications, I get a ton of shit spilled on me. I usually go back home after that bc I cannot stay for 30 mins.

And the other, is when I travel intercity for a doctor appointment, and I need to sit on two sits (so I book and pay for 2 seats). It’s not the question of comfort, it’s a question will I pass out or not during the travel and spend 3-4 hours in severe pain and several days after in recovery. And yeah, I still get tons of shit thrown on my head, like I can do that, imagine if everyone would do that.

Is there anything way to show people that I need accommodation at least to reduce these episodes of inadequacy? I’m tired from explaining everyone that I actually have human right too…