this will sound crazy but it worked for me to at least lessen the allergies. I was the same as you. a whiff of grain dust, and I was sick for days...
A friend of mine who was a chinese doctor told me to start eating with silver or silverplate cutlery, to cook with copper pots, and to lose the stainless steel watch, and to avoid contact of stainless steel with my food or body as much as is possible. Ceramic, or titanium knives, etc.
I have only just used the silver cutlery, and gotten a titanium watch. Haven't bought copper pots yet, or ceramic or titanium knives. I can now unload a semiload of grain, and be in the dust that before would have incapacitated me (coughing, chocking, hardly able to breathe, etc.), and only have a blow my nose a few times. Took about 3 months for that to happen though.
He said if you use silverplate, to make sure that it's really well plated, or get it replated.

__________________
All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic