Violently ill after only 1/2 cup of vodka?

TLDR: I used to drink a lot but now only after 1/2 cup of vodka I can’t even hold water down for 24 hours or more.

Hi all, 21F and about 100 pounds on a good day. I’ve been a heavy drinker since about 2023, but with some few week long breaks in between. I used to be perfectly fine with alcohol, being able to drink as much as I want and not get hungover, I felt like I had a superpower. But now, I usually put about 1/4 of vodka in each of my mixed drinks (it’s the only liquor I can handle the taste of) and even after two of those drinks, totaling out to 1/2 cup of vodka total, I go to sleep spinning and then a few hours later at 3 or 4 in the morning the violent puking starts. I begin by throwing up all the contents in my stomach which then leads to dry heaving for a bit until I drink some water and puke that back up. It turns into a cycle and usually does not stop until the late evening, early night. I’ve been hospitalized twice for not being able to hold down anything in my system for over 72 hours. I’ve done some Doctor google searches and these are possible reasons: -alcohol intolerance -gastritis -I really am just drinking too much for how little I weigh TIA! Pls help!