I am 23w3d and still suffering from morning sickness. I have since 5-6w. At this point the doctor doesn't think it will go away, not until the end of the pregnancy. So, I will be on medication until then. A few weeks ago, I tried not to take it for 2 days, and like you I wasn't able to keep down anything, not even water. if I were you, I would hope it is just the flu.
hope you feel better soon.
EDD Feb 7, 2004