Take some echinacea (you can get it at most health food stores and drugstores) two pills every two hours until you start to feel better. Should build up your immune resistance. Also, go with the Vitamin C, 1000 to 1500 mg/day.

Phinnia the Naturopath

PS - Which kitten is that in your picture (the Siamese - I think the grey one is Mouse if I'm not mistaken?)?