I recommend seeing an allergist. Seafood allergies shouldn't be taken lightly as they can be life-threatening. My DD(8) has anaphylactic nut allergies. In our experience, every reaction is progressively worse. DD now reacts just from exposure to other people who've recently eaten cashews. We carry 2 epi-pens, benedryl, and an inhaler at all times. IMHO, ANYONE with food allergies that have the potential to be life-threatening should be treated by an allergist. If you do not have an allergist, call your family doctor and demand a referral to an allergist. In the interim, your family doctor should prescribe an epi-pen for you to have on hand.
As far as treating this reaction, I agree with everyone else. You should be on a taper of prednisone and should be taking benedryl every 4-6 hours daily for as long as needed.