What to do when you can't tolerate any medications?

Hi! So I suddenly got pretty severe MCAS earlier this year. I have a doctor who is very MCAS aware, but we have had basically no success treating it because I react to essentially all medications (including compounded ones with no fillers) and supplements, even in extremely tiny amounts. I am able to take one specific brand of levoceterizine, but am otherwise unmedicated. It only helps a but. So far I have tried:

Cromolyn Sodium
Ketotifen
Quercetin
Numerous other H1/H2 blockers...

What to do when you can't tolerate any medications?