My eyes are swelling shut. am i having an allergic reaction?

Probably: Sounds like a pretty severe allergic reaction. Make sure you aren't having any problems breathing. Acute onset of eyelid swelling is often caused by allergy. Try some antihistamines and if it doesn't clear up quickly, see your doctor!

Eye puffiness: Puffiness of the eyelids is a common symptom of allergies. This is usually accompanied by itchy, red and tearing eyes. It can also be a part of a more generalized allergic reaction with hives. With allergies, the vision should not be affected and symptoms should improve gradually with antihistamines. There are other reasons for eye swelling that should be evaluated for by an eye doctor.