Convincing a parent about source of migraines?

Hi folks.

I have very debilitating migraines, and I've become convinced that they're triggered by foods containing a high amount of histamine, and/or histamine liberators. The histamine foods list at https://www.mastzellaktivierung.info/downloads/foodlist/21_FoodList_EN_alphabetic_withCateg.pdf is really a big help for me.

But my dad doesn't seem to believe me about this. I'm 55, and I probably understand my own body better than he does - but I also don't want to push back too hard about this, even though he has a long history of not taking me seriously enough.

What would you do to persuade a parent that "this is my body, let me make my own decisions for it", without causing a rift? I like it that he thinks critically, but this really isn't the place for it.

Is there some sort of doctor that could give me a formal diagnosis, one way or the other? I tried an allergist, but she just gave me that checkerboard-on-the-back test and didn't really pin down the source of my headaches.

Thanks.