I started with phenergan, then to zofran and ended with something else. I think it was made to combat nausea after chemo treatments. Ginger is said to help and those prego lollipops. I couldn't find anything that really helped me other than throwing up and the prescriptions.
Vitamin B6 may also work.
Oh, that reminds me! I took the phenergan in the morning, and at bedtime I took a half a Unisom and a B6.
I don't know if this would work, but my aunt did this for her chemo nausea: 8 oz. of dark (red or purple) grape juice. A nurse told her that it would help, and she said it did! You could also try a banana for the potassium.