Sudden alcohol intolerance?

I started drinking a year and a half ago and usually drink on 2 weekends each month and could put drink all of my friends and most of my family. Generally I would feel fine while and after drinking except for the occasional hangover if I went too hard. But the past 5 or so times I’ve drank I’ve started to overheat, get red faced, vomit and have a pounding headache. This has happened 5 times in a row and has happened at multiple levels of drinking, for example after 2 beers and not feeling the slightest bit tipsy and on another occasion I had 8 shots in 3 hours. It feels like having a hangover but slightly different and happens within 2 hours of any amount of alcohol entering my system. In addition a few times this has happened I have drank enough to what would’ve made me decently drunk before and yet I don’t feel the slightest bit tipsy and start throwing up. If anyone has any idea what this is please let me know as I enjoy drinking with friends but it ruins my night when this happens.