After doing some research online I found some neat stuff. I am no doctor, this is what I've read. I encourage you to do your own research and talking to a trustworthy doctor if you have any serious medical conditions.
Ginseng is a common herb that reduces stress, fatigue and increases general well-being. This is found in many energy drinks on the market, however these energy drinks also have a lot refined sugar which is not healthy as I will write about in the future. So I would recommend buying it from a local herb store and having it in a tea or growing it in your garden and learning which parts to use as with most of these herbs.
Echinacea can help shorten a cold or infection and lessen the symptoms. It won't prevent either of these, but if taken at the first sign of a cold it will stimulate your immune system.
Chamomile, a common tea can be used to treat an upset stomach or cramps. It's also helpful for ulcers and stress.
Goldenseal is an anti inflammatory and will help digestive problems as well as many other ailments.
This website is a great reference with much more detail about this stuff.
I hope you enjoy and find something that helps you here.