

That was my thought too. I’ve been dealing with similar symptoms my whole life, and they got worse after covid.
This eventually led to me investigating histamine intolerance, because viral infections can exacerbate all that. The lifestyle changes I’ve made since then have helped.

Good summary. It’s complex, but a good diagnostic starting point is looking up headache diets that eliminate a huge range of inflammatory foods. It’s very strict, but within a week or two it should be clear whether there’s a difference, then you can proceed to figuring out exactly what your body reacts to, and how to assist the DAO process.
In my case, there’s a genetic basis for low DAO production, so you can confirm it with a DNA test, but sometimes there’s dietary reasons.
Some people get relief by using antihistamines, but I didn’t notice much difference there myself. That might lead you to think allergies are a part of the problem, but not necessarily. You can be negative across the board on allergy tests, and still accumulate histamine in the body if it’s not getting removed efficiently.