I'm sorry you're going through this - sick and anxiety is a double-whammy.
Paxiled is right - some medications have a stimulant in them to break up congestion. Even prescription Prednisone can worsen anxiety. I suffer from chronic allergies & anxiety. For me, when my allergies get bad I always have a heightened worry/awareness that I might get a sinus infection, bronchitis, or pneumonia. So speaking from personal experience, yes allergies might make someone more vulnerable to anxiety.
Double check with your doctor/pharmacist on the ingredients in your meds. Drink plenty of fluids. Hang in there!
Is it possible you take allergy medication? Some if it is very stimulating, which could be more of a problem than the allergies as to your anxiety. Just a thought.