Nausea has been one of my worst symptoms for several years now. The only thing that helps it is a prescription drug called Dronabinol (Marinol is the Brand name). The biggest problem with this drug is that it makes me very confused and disoriented. I can't drive, or do much of anything while on it and the effects last for several hours. It does help the nausea, but I wish there was something else that worked without the side effects.
When I had nausea problems I took Uriel Chicory Ginger Digestive Bitters shop.urielpharmacy.com/liq-chiginbit240.aspx
It's all natural with no side effects. I used to take them right before I ate and it really helped calm my stomach and took the nausea away. I was amazed at how well it worked for me. I still use it on rare occasions when I have nausea, which isn't often, but it's very effective and it might be worth checking out and trying.