drinking very little but still getting sick??

so the other night my SO and i made ourselves a few drinks, we just mixed some fruit juice with all different kinds of light liquors until it tasted delicious it was so much fun! anyway we had about three or so drinks and watched an episode of futurama, had sex and went to bed i was feeling really really drunk like i couldn't even walk straight, my SO is a lot more accustomed to drinking so he only got a little drunk. about thirty minutes later my stomach got really really sick and i just felt pukey so i went to the bathroom and just laid of the floor i forced myself to puke a little and then i went back to bed and still had an upset stomach. (the night before i drank even more than i did that night, alone, and didn't get sick at all)