why do I get a swollen throught and nausia every school day?

Every morning before school my throught feels a little swollen. This leads to nausia but I never throw up. This has been happening to me for over a year and I saw many doctors but they said it was nothing to worry about. Even in school I get sick but its worse than at home. My friend thinks its my social anxiety. Im really not sure.

what is happening at what can I do about it?