I don't think that you could have an alergic reaction to fiberglass because the glass is inert and it doesn't dissolve into your blood stream. Glass fibers can imbed themselves into the tissues in your lungs, causing irritation, inflamation and ultimately, destruction of the lung tissues and scarring. That usually happens to people who work around insulation for years. My uncle was an eletrical contractor until the fibrosis got to him. He died a long, slow, suffocating death.
In your case, I would suggest that it is the dried animal feces in the insulation. Animals carry various diseases and you don't realize that the dust in attics has allot of that in it. If you aren't wearing proper safety equipment when working in a dirty attic, you are just asking for problems.
I hope you get better and I hope you have learn to protect yourself.