stomach hurts while drinking

havent been able to find much on google abt this so thought id ask here. so im a pretty big guy and my ethnic makeup is all from peoples known for drinking a lot, and as such i can drink quite a bit before getting drunk. however, i often get an upset stomach and or nausea while drinking that can sometimes prevent me from even wanting to drink enough to really feel it. generally, anything above 20% makes me want to throw up almost immediately though it depends, and i mostly drink beer which usually starts to make me feel shitty after a few (and a few before i Really feel anything else from it). im in good health in every way that seems relevant, and im pretty frustrated w how often i have to throw up and/or feel upset to my stomach when i go drinking w friends especially since i often dont even drink enough to get drunk w them bc of it. thanks for any help/insight u could give