Not GP, but try an elimination diet. I had chronic sinus headaches and cutting out a ton of foods fixed it. My brother is diagnosed celiac, I am not because you have to eat gluten for the blood test or do a stomach biopsy, both of which I'm not down to do.
Changed my life in such a significant way. Doesn't hurt to try it.
Changed my life in such a significant way. Doesn't hurt to try it.