Oh, honey, I am sorry to hear that you are not feeling well. You could take medicine for that. Usually, when I throw up, I drink water to try to "push" the digested food back down. I hope this helps and hope you get better soon!
One you are dehydrated from throwing up, it's a downward spiral. If you haven't kept any fluids down for a day and urine is dark orange, you may need to get IV fluids. Try drinking flat sprite, room temp. Only take a few sips to keep it down. Then increase as able. Saltine crackers help or toast w/ bit of honey, no butter. Use a measuring cup and track what you are able to keep down. 3 days of no fluids is intense and should be under doctors orders. I am not a doctor but well versed amateur.
After you throw up, don't take anything by mouth for at least 20-30. You have to let your stomach rest. Get some Gatorade or even pedialyte to replace the electrolytes you have lost. Just take small sips until you can hold more down. Be sure not to get dehydrated. I hope you feel better soon.
I am really sorry that you are throwing up. Why are you throwing up? To control nausea, don't eat or drink anything for half an hour then take a sip of hot water or hot tea without sugar. Wait for a few minutes and if you keep the water then take 2 sips, then wait, etc. If you have Zofran ODT, put a pill under the tongue. If your urine is dark amber in color, it means you are dehydrated and need fluid and maybe electrolyte replacements intravenously.