Have you tried prescriptive options, like zofran?

ginger! literally just mix a 1:1:1 ratio of powdered ginger, brown sugar, and warm water. I tend to go for 1/2 teaspoon of each. Coat your tongue with honey and swallow the entire ginger mixture in one go. That's been the only thing that's ever helped me because I can't take antiemetics and the relief is just about instant. If you don't feel like being an alchemist, DGL (deglycerrhizinated licorice) is available at any health foods store, although it's a little expensive. You can also order it online