why so sick

I drank last night I had about 7 beers, it made a little sick like getting the spins, and all day I feel like shit. My head doesn't hurt that bad but I feel so sick that I'm ready to puke any minute, and even thinking about it makes me want to vomit. The problem is, I can drink that much like I do once a week and I'm fine. So I don't know why all the sudden I'm this sick. Any thoughts? 
Edit: I drank water through out the day yesterday and I ate before and had a glass of water before I started drinking. And I had the same think I always drink. And I drink about once a week maybe have two beers less or about the same. And I've been drinking water all day, and ate and I still feel sick.