Why does alcohol makes me so nauseous all of a sudden

I downloaded Reddit just for the purpose of this question I have. I used to drink a lot. One day I overdid it and I ended up in an alcoholic coma.Ever since I’ve been grossed out by any alcoholic beverage in a way that I can’t even put through words. I’ve tried to drink again but the nausea it makes me feel makes me want to puke. Why does this happen? And how do I fix it?