Unsure of what is wrong with me?? Not even the Dr. has been able to figure it out!?

I have had a fever >100 for the past three weeks. At times it gets as high as 102. The only problem is, I feel fine. I have been back and fourth to the doctor and my WBC's are at a good number, my urine is good, and I have no pain. I do not feel sick, the only symptoms I have are feeling EXHAUSTED all the time, waking up in the middle of the night going from freezing to sweating every hour and feeling slightly confused at times. My doctor has tried 5 different antibiotics to see if maybe I do have an infection somewhere and its just not showing up, but still after completing the regimen, I still have the fever. Any ideas???