Thanks for your responses. I'd been with this person for 5 years and broke up permanently a few months ago, He was emotionally abusive. I became adept at compartmentalizing. I would be easily persuaded by how high-functioning he presents himself to be and I got very used to being gaslit (and gaslighting myself) and the smell of booze became the norm.
Today it was a huge trigger for me as he'd been sober since we broke up but evidently back on it. As I said, it is bizarre that I focused heavily on the dietary stuff as oppose to the drinking. Perhaps because I know I will never ever be able to control that. Maybe for a moment today, I thought I could control 'something' else... like the food! As you said sage - that's something I need to let go of and don't have any control over.
He drove to my house expecting to drive my son back to his parents. He denied being drunk but when you smell alcohol off someone like that, they're obviously still drunk but something happened in my mind... old pattern of normalising it. And so my mind switched to the other less significant issue. Cognitive dissonance here I'm guessing. Whatever happened in my head, i'll thank my inner voice for refusing point-blank to let him take him. I take that as something shifting in me.