How many allergens did your doctor test you for? Did you do a symptom diary to try to choose which antigens to test? What about exercise-induced asthma?

You might try putting allergen-blocking covers on your mattress and pillows. Some of them aren't super expensive, and they rely on a high thread count plus a thin coating, rather than the thick crinkly noisy covers they used to have. It's made a big difference to me.

I would think any food allergies would've shown up on the serum IgE - which I think tends to have a lot more false positives than false negatives - but you might still try a challenge diet, as well.

If your doctor isn't an allergist, I think it's definitely worth seeing a specialist.