I get food allergy headaches so you might want to check for that mostly processed foods but anything aged or moldy or processed foods especially msg in all its other named forms modified food starch, autolysed yeast extract. Anyway anything you are allergic to could do it. Interesting note I recently looked up copper toxicity and found that most migraine sufferers have high copper and lead levels, oddly enough I do and I also have highly acidic water 5.0 neutral is 7.0 and I have copper pipe and green sediment. Oddly enough I have never seen any indication of this in "mainstream medical education".
I went to the shore recently and felt good, better than I have in ages towards the end of the week I barely needed any vitamin c (which I use for allergies) and I wasn't eating like I should. Apparently vitamin c works against copper. I very soon will be getting a neutralizing water treatment system. I have already ruled out vitamin D and Sea Salt as the problem. I hope this helps however mercury has the same symptoms as copper.