Personally, I never wear one outside. I've been working from home, so no issue there. I have been wearing one in businesses, I would never drive a car with one on.
From my understanding, not a single law has been passed in the US making masks mandatory. It's all been under "Color of Law," but as you can see, many, many people have accepted this idea (as have almost all businesses), so it seems to be a technicality...... but a really important one that is a huge asset to you if you decide to fight back.
As for your job..... that's going to be a tough call. I can see lots of options. You can submit, of course, you can continue on as you are and see if they make a big deal, or you can fight them on it. Print off a few studies from Pubmed (using Sci Hub, if needed) showing masks are useless, and confront them with that data. Maybe a simple conversation about your concerns (with backup studies) is all you need to do. Alex Berenson posted a great one today- A cluster randomised trial of cloth masks compared with medical masks in healthcare workers
Use older CDC guidelines- https://www.cdc.gov/mmwr/volumes/66/rr/pdfs/rr6601.pdf
And "pandemic" studies- https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.552.1109&rep=rep1&type=pdf
Find those videos about OSHA oxygen levels, push them on that, go to OSHA for clarification. Buy a UV flashlight and show how infected those masks get couple good examples here-
File a health complaint with HR EVERY SINGLE DAY if push comes to shove, noting that fatigue/performance suffers after 20-40 minutes of wearing a mask, and you are starting to notice lung inflammation/problems, and you feel it's directly related. I'd personally save this for a last resort.
A Ray Peat Forum Revolt! And if it does cost you financially......... @Regina posted a video about how to fill out form 95 that you may be interested in.
I'm starting to think maybe the move is move into a Yurt or something, like this guy-
I like yurts but I think bears can rip it open. No?