HIGH FEVER again

the last 2 days have been really bad for me. since monday i have been running a very high fever. on monday i had to go to the emergency room after which i got admitted to the hospital. the  fever is getting high as 103.9 and will not come down to normal. the fever might get down to 100 but instead of going more down to the normal 98.6 it will again increase. the last 2 days have made me really tired. the doc did all my tests like blood test, x-ray, ct scans and all was normal. the doc could not find a cause for my high and on going fever. i did have fevers before but nothing like this one. my temp never raised so much like this. when i used to take fever medcine it would come down to normal but this time its just not coming down. since the last 2 days the mininum temp was 99.9. im just praying to god that my temp will be normal soon coz it has made me really tired...