I checked Worsened 'hangover' effect the next day + Upset stomach - soon after + Aggravation of ME/CFS symptoms soon after + Other unpleasant symptoms.
I can't drink more than approx 6 cl of wine nowadays. I still enjoy the taste, though.
The first time it happened to me I was travelling solo in a south western European country, having dinner and a small glass of wine at a restaurant I hadn't visited before. I genuinely thought I might have been poisoned, but managed with very great difficulty to get back to my hotel. The symptoms eased a bit after a few hours and I fell asleep, I never called an ambulance.
I get a very strong reaction after about 15 minutes or so, as if I've been poisoned. Extremely nauseous, super dizzy, vomiting, spaced out/lightheaded, difficulty thinking, balance issues, eyes affected too (difficulty focusing and processing), muscle weakness and shakiness, feeling as if I have an immense hangover (also very soon after, like half an hour after drinking).
I've experienced all sorts of stomach issues while travelling before, like "Delhi belly" and "Pharaoh's Revenge" and all those things. But my reaction to alcohol was something completely different.
The intense poisoned feeling lasts a few hours, and the "hangover" effect continues to the next day with added PEM beginning after 24-48 hours. If I remember correctly, it's been many years now. I didn't realize it was alcohol intolerance, until the second time it happened.
I never had a hangover before ME.