Why do i get so nauseaus when i drink with zoloft?

I'm 14, 5' 7", and 140 Lbs, female, and i'm on 50 mgs of zoloft every day for depression and anxiety. But lately, whenever i drink, no matter what i'm drinking, no matter how much i drink, i get incredibly nauseaus for hours and hours, and most of the time i end up throwing up, often until i have dry heaves for a while, and then eventually i feel better. Why do i get so sick? last night i had just a tiny bit of red bull and vodka around 230ish and i threw up at like 6 in the morning. is there a reason why this happens? and can it be avoided? thankss:)