As much as people want to say dont worry, things don't always turn out rosy because you want them too. People get sick for their job interviews and it can cost them that job. It may not particularly be your fault but it doesn't really matter. Were you able to determine the cause throwing up? Do you have bad sleep patterns or eat poorly? Were you out drinking all night? If you don't take care of yourself then you really don't have anyone else but to blame yourself when your health gets you in trouble.
If you plan to stay you need to work at your peak to impress, and the holiday is a marathon. Just like in the olympics, for several weeks you need to sleep right and eat right to be at the top of your game.