Vitamin B6 helps with nausea. Don't let yourself become dehydrated or hungry, both will only make it worse. Lots of rest, eat something with protein before you go to bed and before you get out of bed (cheese, nut butter, whatever works) in the morning. Eat whatever sounds half way decent until this passes, and it will pass. If you feel like you are becoming dehydrated go to your doctor immediately. I've had hyperemesis with three pregnancies, absolutely miserable and enough to give a person PTSD.