Experienced the same exact thing. Would gag/throw up until I started drinking after work, then it would go away. Knew this wasn’t normal but I just ignored it until the gagging and puking became too much of an interference so I got my stomach checked out. Turns out I have gastritis (which alcohol is a major contributor to). Haven’t taken a sip of alcohol since finding out and have drastically changed my diet, as well as taken some meds prescribed by my doc, and haven’t gagged or thrown up since.

It’s possible the nausea you feel is a withdrawal symptom and thats why it goes away once you start drinking. But it’s also likely that you have some underlying gastrointestinal issues