First thing Not to do; Soup is actually a No-No. You can have a little soup but it won't make you get better. Soup will slow down your white blood cells causing you to recover slower.
Also try to avoid any kind of gatorade. It doesn't help because of all of its sugars. Stick to tea for right now.
Fruit actually is not the best idea because of the sugars. Fruit is normally great because of its natural sugars but if you are sick it might slow down the proses un like vegetables which will cause your white bloods cells to speed up, veggies also help fight off all those bad germs.
Things to try; I know that people thought that vitamin c was good for you and then the thought it wasn't but actually anything with protein or vitamin minerals are great. So eating broccoli or having lemon tea is actually quite good for you.
LOTS OF SLEEP, i know its hard sometimes to sleep when your tummy feels so active but sleep is the best remedies for a cold/the flue. Also water, water is very important cause it will clean out all of your bad germs. Water also prevents head aches. If you can stay in the sun for a little bit, i know that if you live up north its hard so maybe this is not something that will help you but if you live in the south you should stand outside for a a few minutes just to get a little fresh air.
There is a great video that you should try that explains all the great effective remedies for sickness.
So that is how to recover form sicknesses. I hope it helped sorry i am not a doctor. I will post art monday later today around 6:00-7:30.