Sherry's right. See an allergist, and supplements probably won't help.
Do you get headaches from eating anything else? Keeping a food log/diary with the date, time, what you ate and your reactions after 1 and 2 hours, maybe even a day in the case of headache reaction.
Food allergies can be acquired from eating a lot of a thing, or even inhaling pollen or dust from the food or seeds.