I have a swollen gland on the right side. can this be an allergic reaction to food or medication? could it be a cold? throat nose and sneezing a lot

Swollen glands: Yes, a swollen gland could be all of the things you asked about, such as an allergy, cold, etc. It is more likely to be a viral process or allergy to pollens than food allergy, especially since you are having throat symptoms and sneezing. If you have allergies, try an over-the-counter antihistamine first as this could help with your sneezing and the scratchy throat. If no better, see your doc.