Ginger is your best bet. Also the cheapest. Most groceries sell it in the produce section, near the snow peas and such. It is a root with a papery looking brown covering. You want to slice off a disc or three about the thickness of a dime or a nickel. You put these in a mug and pour boiling water over them, like you would for tea, and then you let it sit for a couple of minutes. You can add honey if that helps your stomach. It does for my daughter, it doesn't for me.
Ginger is one of the most effective things you can use for nausea. YOu can use the root this way, you can also use dried ginger like you buy for cooking, either in water or mixed in a teaspoon of honey and swallowed, or you can buy candy made with real ginger. Often I see it in health food stores (gingies is one brand) and of all places at TJ Maxx in the gourmet food section (not necessarily that brand, but various brands of ginger candy made with real ginger as a main ingredient). My mom uses the gingies candy when she gets migraines and it is one of very few things that works when the nausea hits. It works better than even the rx medications. I do better with the ginger root and hot water, and it even worked for morning sickness - and it is safe for morning sickness just like ginger ale is safe.
I hope one of these suggestions helps you. Don't feel you have to buy ginger in whatever size the pieces are in the store. You can break off a small piece to try if you are not sure you want the whole piece that the grocery store has. It is sold by the pound and people regularly break off pieces so they only buy the amount they want. At least they do here. And even our Walmarts carry it, so most stores seem to carry it.