Hello, I understand your pain and it seems that it is bothering you too much. Usually migraine affects only in one side if the head and rarely it is on both sides. It associates with nausea vomiting, too much stress when you have stress there would be pain in your stomach h because of the hyperacidity. Yea as you said there is also relation of digestive system.with headache when you have more gastric secretion then you may get headache but it would be mild. You can consult a general physician or a neurophysician. Thank you