Ahhh, the alcohol issue. I'm currently working through this... Everyone always thinks is pills they take or this or that... Theres a checklist to look thru if drinking any amount of booze is making you sick.
-ulcer
-allergy
-anxiety
i found mine was anxiety. I am (or was) a big drinker. Where I could have 10 or 11 beers and endless shots without ever puking. And one day even I had half a beer and emptied my guts out. So after getting tested for ulcers, refulx etc... I discovered it was a social anxiety that literally developed over night. The only way to really cure that is therapy. But next time ur around booze really take a minute to think about it. If it is just you convincing yourself that you will be sick, and therefore you get sick. Since I dot have money or time for therapy, what I do before I go to a party, is make sure I go seperate from my friends so I can leave whenever I feel I wantg to or need too, seconly, I always go an hour before everyone else so I can make myself comfortable in the situation I will be in, and after about 30 minutes of familiarizing myself with the place, I have a couple drinks and then I am ok once all my friends show up. If you are thinking to yourself "well I dont wanna seem like a big loser and be there an hour bymyself", do something productive with that hour. If its a house party I always go and help set up, or if its a club I order a sandwich and watch the game if im gonna be so early. You should really give it a try, and make sure you use mental blocks and dont think about being sick. Just keep yourself occupied the entire time. Be relaxed and dont stress yourself out, and the nausia will go away. Good luck!