Sore throat after vomiting?

I vomited all day yesterday. At first I thought it was a hangover because I had done a bit of drinking the night before, but it felt different and lasted way too long. (Almost all day) I also ate some oysters the night before so it could of been food poisoning or a bug of some sort. My throat hurt pretty bad afterwards but I figured it was because I had thrown up so much. I just woke up from sleeping and now my throat hurts even worse and is pretty red. What could this be? (Vomiting has stopped and I feel much better in that aspect)