I have a severe allergy to shellfish, so I'm afraid of other seafood. Any advice?

Get tested. Get tested for lots of shellfish and fish. You may be negative to seafood items you like and are afraid to eat. Then bring a sample of food you want to eat to the allergist's office and have a challenge to be sure it's safe to eat it. Be sure to mention your allergy to any restaurant where you eat, and carry your epipen (epinephrine). A cooking spoon may cross-contaminate a dish, so safest place to eat is home.