Sinusitis or not causes low fever and great fatigue

I have been sick for about 3 month. I have first caught a cold and afterwards I would always feel very tired with low fever. The fatigue and fever(come together) appear every 20 to 30 minutes. I feel ok when I sleep or lie down calmly, but once I start doing something, even reading something carefully in bed, the body temperature rises and I feel very tired - cannot work at all.

Spent 1 month in hospitals doing all kinds of tests. Finished with doctor on ears, throat and nose. Made there all kinds of tests, including x-rays of the sinus, which was ok. Doctor said it was decompensated tonsillitis, so he removed my tonsils about 2 weeks ago. Nothing changed about fever and fatigue. Still have some kind of drinage at the back of my throat, which, as told by two doctors, is coming from nose, but cannot be causing any of my symptoms. The thing is that i breathe ok, don't have a running nose, but there's still something draining back of my throat all the time. What is it, when x-rays show it is all clean???

[National Jewish]

It is possible that the sinuses are inflamed and this did not show up on an x-ray. Sometimes, you need a CAT scan to see this inflammation. It is not uncommon for inflammation to persist past an infection and produce the kind of problem you are describing. I would speak with your physicians about having a CAT scan and also using nasal inhaled anti-inflammatory medications in an effort to control these symptoms.