Hey,
I'm also autistic, and struggle with wearing face masks due to sensory overload. I find it very sad about all the judgement being thrown around at people with autism. However, I have found out about powered face masks which use a ventilator and batteries, so you constantly get filtered air from outside (you can get them on Amazon). It works for me (at least when it still has battery). Here's the one I use: https://www.amazon.com/Breathe-Promotion-BROAD-Air-Purifying-Respirator/dp/B086DM52NK/ref=sr_1_38?dchild=1&keywords=face+mask+air+pro&qid=1597960473&sr=8-38, I'm sure you can find others.