Sorry about your ordeal. 14 hr migrane sounds awful. Did you ever suffer migranes pre MC?
It would be mostly second guess as to what might have casued it and quite often it's not any one thing but a particular combination of things. It could also be somethng you did the day before. While I absolutely love seafood it can get tricky sometimes if one is not super careful about making sure it's very fresh. The worst times I've had geting sick have been from seafood. The giant cookie. Well maybe. You gonna go through lots of trial and error while you find your groove. It will always be a "work in progress"