Help, cant proccess alcohol anymore?

First post, recently after having an alcoholic drink ive been feeling sick and had a constant sore stomach that wont go away. I had just finished a meal yestarday and started drinking around 20mins after. When i go to be sick, nothing comes out, maybe a little spit but mostly just dry heaving. I didnt drink too much and this never really happened before. Its like my bodys rejecting it now. Whats causing this?

The drink i had last night had caffiene in it and tried to drink it a bit slower, but thats lead to a bad sleep, i started getting stomach pains around 4am and hasnt gone away, and tried to be sick around half 5 with no result.

I enjoy drinking and wouldnt like to just give it up entirely. Im not on any medication or started any new meds