Omg I feel for you...try frozen Popsicle pedialyte that helped me and just stay in bed and try not to move around to much or go into a car I hope u feel better and can start eating soon..also have your OB or midwife try vitamin b6 unisom zofran or promethazone...and see what they say anyways I'm wishing u the best I went through all 4 of those medications before.
Water induces vomiting, try something like ginger ale or Pedia lite, gatorade is good too. I know it's tough but if you can keep any of that down you'll at least stay more hydrated.