You'll definitely want to consult a doctor, not a website.
Try to eat light, and drink water. There's not much more to say until this is diagnosed.
Hi!
Though a rare disorder, pancreatic insulinomas should also be thought of in your case and have someone check your blood sugar while you eat. The hypoglycemia in this is transient following food and there is a quick increase in blood glucose once you eat.
The other possibility is a bad gastric reflux. Drink cold milk. Avoid heavy meals and eat frequent small meals. Avoid too much of caffeine, tea, smoking, fried food and drinks both alcoholic and non alcoholic fuzzy ones. Avoid heavy exercises within 4 hours of a heavy meal. Raise the head end of the bed by pillows to 30 degrees. Avoid lying down for least 2 hours after food. Take a late night snack. Maybe these tips will help you. If they help you, then please consult a doctor for further treatment.
Another possibility is that you have an eating disorder. So, if everything else is ruled out, then you must consult a counselor. Hope this helps. Take care!