Put off?

This weird thing has been happening to me for a while now. I used to be able to down bottles of vodka, wake up with a hangover and repeat. But since this party I went to 1 month ago from now, even just the smell of alcohol has made me want to throw up. I can’t drink anything stronger than a beer without tearing up and gagging. Just want to know if this had happened to anyone else or how to fix it.