Why do I get nauseous when I smell good cooking?

I recently got a job as a dishwasher for a local food restaurant. It's a high cl restaurant that serves seafood and other exquisite foods. I hate seafood with a pion, so this might be the reason. Whenever I'm washing dishes or smell the smell of the cooking area, I get nauseous. Today was the most severe case, it started off with a headache than my stomach starting feel squeemish than I vomitted. Anyone know the reasoning for this?