I've tried every diet out there, including vegan, and I do stick to them as I have good self-discipline and am not really hungry at all ever, mostly I'm just happy when I can keep the food down, don't care what it is and I won't risk it with too much sugar even when not on a diet. But no, no food triggers that I can identify. It seems to be more regularity of eating that triggers it, I can't eat too much or too little but what I eat doesn't seem to matter.
Less toxic surroundings - not a possibility, I have zero cash, I can barely study anymore and I doubt any career will be an option, ever, with my condition.
Caffeine makes the headache a bit better actually, I take pills with caffeine in them. I never drunk coffee when the migraines started, just by accident discovered caffeine makes it better.