Yogurt (yep, the ones in the plastic cups) helps with yeast infections.
Ginger is aces for nausea. You can even just steep a medium-sized piece of ginger root in hot water, sweeten to taste (if needed) and sip it. You can buy ginger root from farmers markets, international markets (especially if you live in an area with a significant immigrant population) or maybe even Whole Foods and the like.
This may not be very natural, but...my grandmother always tore off a small piece of a paper bag, dampened it, and applied it to the middle of my forehead when I had hiccups. STrange, but it stopped them.
Garlic is great for the immune system and also helps lower cholesterol.
Witch Hazel is excellent, especially for oily skin.
Bananas are great for heartburn.
T.