Hi I'm AuDHD (autism ADHD) it is not inherently autistic to find places like grocery stores discomforting, as they are meant to be discomforting, as your decision making is heavily reduced when you're overstimulated, and thus customers buy more product, or the wrong product so they have to come back and buy more, etc.
I do get overstimulated and sometimes overwhelmed by grocery stores, yeah. If you have any questions about this, or autism, or ADHD, feel free to ask!
Have a great day and be kind! :D