Is this alcohol intolerance?

I need help figuring out what this is because I have never seen or heard anyone experience this. I drink occasionally but have never been a big drinker, and every time that I drink (any sort of alcohol), I get a terrible stomach ache after a few hours of the effects wearing off. I also start to shake sometimes during the stomach ache, and always end up throwing up at least twice. This happens both if I take 2 shots or if I drink 10. I have tried antihistamines, drinking absurd amounts of water, eating a lot beforehand, sleeping while still feeling the effects, or staying awake, and I still have not found a solution to this or even figured out what the problem is. Does anyone have any idea?