Why my urethra is feeling discomfort -- 3 months

[Stcroixav]

I having this intermittent burning / sting feeling around my urethra and penis in the past 3 months. The symptom is more obvious when I sitting for maybe an hour or so. No discharge, no sore.  Past medical check up as below.

I was diagnosed with gonorrhea in July and treated. Potential exposure week was probably 26/6 - 2/7.

I did a blood test in on 6/July (i.e. 1st week post exposure).  Negative result for syphilis, herpes 1&2, HIV, and Chlamydia.

Another blood test on 28/July (i.e. 4th weeks post exposure). Same negative result for all the above mentioned

Doctor has prescribed various antibiotics for the symptoms, including doxy, metronidazole, azithromycin.  But all does not relieve the symptoms I mentioned above.

On 14/Sep, i did a culture test (urathral swab) and found klebsiella Spp. No gonorrhea found. Doctor gave me cefuraxime 1g to be taken everyday for 10 days. Sadly, no improvement at all after 10 days.

Visited urologist on 25/Sep. Upon physical examination, the doctor rule out the possibility of herpes and syphilis and advised stop taking cefuraxime. Pending result from urine C&S test at the moment.

What other possibility that causing the symptoms that I am having now? What type of test or diagnosis should I perform to identify the problems?

Thanks !

[Stcroixav]

Update: urine C&S test show no bacteria. WBC normal.