am i allergic to alcohol?

I used to drink like a maniac back in my late teens and younger 20's going out casually like most normal people do...was never an alcoholic type or drank too much type but when I drank I had fund and I'd throw em back...well I'm 30 now and for the past I'd say 3 years I've noticed beer just does NOT agree what so ever...if I drink just 2 beers I quickly start feeling like I drank 26 and I have to throw up for hours on end until its compeltley left my system...i'll be literally throwing up for 3 hours at a time just throwing up slamming water and crackers or something just to have something to throw up but that flu like puke feeling doesn't go away until I throw up violenty for hours...last summer I drank just wine only and I was realy good no hangovers no puking...then I tried going to liquor like mixed drinks and the same reaction w/ the mixed drinks happened like it does when I drink beer so im just clueless...I went to my dr to ask...he replied with the typical "don't drink" response...but Im a man and I enjoy a drink here n there and would like to actually know what this could be...I shouldn't be throwing up like I have the 24 flu just for throwing 2 beers back.

I'm allergic to alcohol. I go in to anaphylaxis instantly. I can't even use mouth wash because my throat swells.

My brother drinks beer constantly. He has a rash on his upper torso. Could this be because of his drinking? Possible alcohol poisoning?

I was just wondering why every time I drink hard liquor, which is often, the next morning I vomit pure yellow bile. I don't think I've ever vomited anything else. Is this bad? What does it mean?