I have to ask if you've had any allergy tests(food and environmental?)
Didn't know if this was a part of your CDSA you mentioned a while ago.
In addition to my MCS I have a wicked dust mite allergy, this is by far my worst allergy (according to the severity and my antibody tests). I work in IT so from time to time I deal with dusty equipment, I had to be very careful. Dusty areas will cause extreme shallow breathing for me.
Besides the blood tests, I had a test done for multiple environmental allergies called a "scratch test" (done topically). I had this done at my doctors office. They put 90 common allergens on my upper back via plastic pins, they then watch for inflammation.
This revealed about 13 environmental allergies including grass, molds, and other weeds. Wish I could post the picture of my back, looked horrible. I really don't have trouble outdoors at all but the dust can be serious for me (at home, office, etc.).
Pro-biotics are the only things that actually helped my MCS a little. I'm not sure if thats an option for you.
What did you Doc say in regards to your CDSA results?