Day 4 of gastro and I still feel nauseous 22F

Contracted gastroenteritis (vomitting & diarrhoea) on Monday, vomitting stopped Tuesday & diarrhoea has slowed down a lot but I’m still insanely nauseous. I can’t eat anything or even look at food without gagging, should it be better by tomorrow (Friday)? I also have my period rn so I am not pregnant lol, but I also have pcos, could that contribute to my symptoms at all? Thanks everyone 😇