Suggest Treatment For Penis Pain While Urinating Or Ejaculation

Could you please advise how the following can be treated: Pain in penis when urinating or ejaculating, Sperm colour has changed to a very light brownish colour, sperm has litle particles. In addition to this, from time to time I suffer from boils in the pubic area - these normally disappear after some time. From about 2 years I started having pain on my lower back but only in the area around my left hip, I don't know if these are related. This sometimes makes it difficult for me to sleep at night. I get tired of sleeping, I've even changed my bed but the problem still persists. I have had this problem for over 10 years now, no docter has been able to sort it out for me. They've even inserted a camara through the penis to see if there's an infection and all the time the tests come out negative.