I always feel cold at lower back, expecially after ejaculation.
 Have done semen test but found nothing. Urine test is good.

That must be a nonbacterial prostatitis. It is prostatitis symptoms that you have cold lower back. This condition also shows a weakness of the kidneys.
Diuretic and Anti-inflammatory Pill can cure you. 
This is my patented herbal medicine with about 50 kinds of herbs in its prescription. You can get cured in three to four months.                                    
Released in 2011-09-09 10:24:25