Using an EpiPen that has expired is mostly discouraged but is better than no medication in emergencies.There is no alternative to
epipen in
case of anaphylaxis reaction but if a mild allergic reaction is there then oral or intravenous antihistaminic and steroid can be used.
Thirdly,from your symptoms it looks like you are allergic to crustaceans. Crustaceans are aquatic animals that have jointed legs, a hard shell and no backbone, such as crab, crayfish, lobster, prawns and shrimp.