Dehydrated while Pregnant...what to do?

So, Im 9 weeks 3 days pregnant. I throw up ALL DAY. It really gets to me. I hate vomit. Anyway my dr said for me to drink 8 cups of water a day. I sometimes feel dehydrated, but every time I try to drink water I start throwing up. I cant' drink ginger ale that good either. The only thing that settles my stomach is pepsi. Any ideas on what can make my stomach feel better.