Abdominal pain after very little drinking

Hi,

I have had problems drinking as long as I can remember. Even after one drink, my upper stomach will start having extreme pains. Normally I stop as soon as this happens and it will go away, but as obvious as that sounds I am now 21 and would really appreciate to be able to drink with my husband. I just returned from a festival because I had literally half of a 20 oz alcoholic drink (bacardi twisted cherry) over about 15-20 minutes and my stomach hurt so bad I considered going to the ER, which is not something I take lightly. I plan on going to the doctor, but I -DO NOT DRINK- often at all. This isn't from binge drinking or ANYTHING. I literally have only been drunk maybe three times in my life and any other time is futile because of my stomach. Also, I am a decently healthy individual and exercise for 1.5 hrs about 4-5 times a week.

Please don't post any unhelpful information like 'stop drinking' or 'go to the doctors' because literally I do not drink often at all and I would just like to know if anyone else has this problem at all or knows what it could be.