Constant high white blood cell count

I am a 44 yr white male, have smoked since late teens and have a constant high white bloode cell count that bounces up and down and back up again between ( 11k to 30k ). My other symptoms are headaches, fatigue, and daily light headedness. I have been to a hemotologyst/oncologist which took a bone marrow biopsy with negative results, also many blood test with that same high white blood cell count from 11k to 30k, no diagnosis just take more blood test. Also seeing a infectious specialist who put me on a daily IV PIC for 3 months resephin and vibative (not sure the spelling there. Blood was tested weekly while on the IV PIC and still bounced up and down, not ever getting lower then 11k, also did a stomach CT with nothing negative found. Also seen pulmonary specialist with a chest CT that resulted in 3 non calcified nodules about 3 to 4 cm I believe, told they were too small too scrape and biopsy. Second CT showed no change, white count still high. Also seen a neurologist for the head aches, did 2 brain CTs that showed nothing negative, and a neck CT that showed some issues that made him believe that was the cause of the headaches, but surgery was not needed, he prescribed 200mg Celebrex and some muscle relaxers. I have had so many blood test, cultures, CT scans with still no diagnoses, everything except a Colinosposy. Not sure why there still is no diagnoses or if I need to be worried and where to go from here. Any real help or experience with the same issues out there. Please help......