When yer done pukin' get some gatorade (sip, don't gulp) and lay low for a day or two.
And if you think you can stand it try to eat something with a lot of water in it - like soup, jello or pudding. If that goes OK try crackers or a banana. Go slow, stop if you start to feel puky again.
PS ~ your stomach feels "hard" cause all your abdominal muscles are clenching. Throwing up is like an ab exerciser from hell.
(And stay out of yer parents' liquor cabinet . . . J