All you need are three simple ingredients - a piece of fresh ginger root (readily available at your local Asian supermarket, most other supermarkets as well as green grocers), one lemon and some honey.
Grate a piece of fresh ginger root that is about 2cm long into a tea pot or bowl. Pour over about one cup of boiling water. Cover and allow to steep for about three to four minutes.
While you are waiting for this to happen, place about a tablespoon of fresh lemon juice and the same of honey into a mug.
Once the ginger has finished steeping, strain the ginger tea into the mug. Stir to dissolve the honey, adding more honey and lemon juice if desired.
This simple remedy tends to be very effective. Lemon is high in Vitamin C, and full of phytochemicals whcih are plant constituents that help boost the immune system. Ginger and honey are also well documented to help the immune system.
Alternatively, I find that my local Asian supermarket sells ginger tea, to which I sometimes add a slice of lemon.
Learning Herbs offers a number to treat colds or flus holistically, as well as offering free ebooks. And if your symptoms persist, please see your medical practitioner - these days many are very open and accepting towards holistic practices.