Viral flu for 10 days. Still have fever of 37.8 and now face pain on right side. Cough. Tight throat. Why am I still sick? Breast cancer? Sore lump.

Sinusitis. Sounds like a sinus infection. See MD who will likely obtain xrays and prescribe antibiotics.
Nasty flu season. We're having a serious flu season. Do you have a cool mist humidifier? Fill it with one bottle of hydrogen peroxide, and two bottles of water. That will give you a 1% aerosolized mist of hydrogen peroxide. The peroxide kills the bugs on contact (virus or bacteria) as you breath in the mist, and breaks down into water and oxygen. You should feel better in a day or two.