you are allergic to fish. this very thing happened to me many years ago after eating orange roughie. then i noticed i would get nauseated just eating tuna or any other kind of fish. also fish oil supplement for omega 3 caused vomiting. now i avoid fish at all cost. for omega 3 i take flax oil capsules. it's a bummer but it can be dangerous.
just recently when i ate fish within a few hours i had very strong vomiting and diarrhea my arms and legs were tinglely. i started getting very warm and then my arms and legs were tingling and then i started very strong vomiting during this time i was able to understand what people were saying to me i was just not able to respond i was unable to sit up i had to be laying on the floor. this lasted for about 45 minutes. i was unable to clean myself up my husband had to do it then i had diarrhea and it has continued today. shortly after the diarrhea started i was able to get to bed. i i laid still i was ok.