What Causes High Fever At Night And Pain In The Upper Back?

I ve been running a fever since May 24th. Comes mainly at night -has been as high as 103.4 Aspirin helps, but it always comes back. Pain in upper back and across chest. Was constipated - no longer an issue. Extreme exhaustion. NO engergy. Slept a lot at first - now having great deal of trouble falling asleep. Pain started on right thigh - no it goes up into hip, across buttocks, and down the other leg and thigh. Very weak at times. Force my self to do things around the house - or I d lay around all the time. Dr. thinks it is a viral infection. Take lots of fluids, aspirin, and rest. She did order a two view chest x-ray and a CBC - both of which were negative. Hate feeling do low - praying this will not be my new normal. Something just isn t right.