Interesting. I travel the world like you but, unlike you, rarely get ill in Perú. Always thought all that traveling exposed me to all the various strains of bugs, heightening my resistance. Maybe you might want to check out if your immunology has recently dropped, given your story line.
Indeed, I haven't been sick here for many many many years and I eat everywhere because of travel. Last time was like 15 years ago when I got it bad, needed intravenous re-hydration. But not from street food. It was food/water from a nun (was staying in a nunnery). Learned a life lesson: never trust a nun.