"I can't figure out if I feel like crap because of the crappy air quality or just the fact that I hate the fast food industry with a passion."
It's probably a bit of both. I used to work at a Tim Horton's here in Canada. I hated it so much! When I first started working there, I had already been Paleo for about a year, and my asthma was almost non-existent.
But as time went on, my asthma came back. I didn't eat a damn thing there (I always brought a big bowl of sweet potatoes and coconut oil with me to my shifts. My co-workers thought it was weird and laughed at me while they shoveled bagels and breakfast sandwiches down their throat).
Anyway, I started to suspect that I was actually breathing in gluten from the air during my shift. I did some research online and read some case studies of people with celiac having to quit their bakery jobs. Long story short, I eventually quit the job with a huge smile on my face, telling my boss I was breathing in gluten from the air. She didn't believe me, of course, but I didn't care. I hated the job and it was an awesome excuse out of it.
The best part was that the VERY NEXT DAY, the Metro grocery store that I had applied to earlier that summer called me up and said a position had opened up for me... in the meat department. One week later, I was serving ground beef and fresh salmon to customers ;)
So my advice, quit the job if you hate it that much. Find something you like doing. Life's too short.