Yep, definitely if you're not holding down fluids. My first pregnancy I managed to avoid it by just taking a mouthful of water at a time, enough to wet the inside of my mouth and keep it down, gradually building up to a decent swallow every 5-10 minutes.

Foodwise try very small amounts frequently of gentle foods, but if you can't keep anything down for more than a day or two I'd think about at least checking with your doctor/midwife.