Good evening, I am Dr Helen, a UK doctor. I work in both GP and cancer care.
Firstly I would like to offer you some reassurance as you are clearly now very worried.
As your own GP said a PSA level of 5 is only very slightly raised as the normal range is up to 4.The so called "free PSA" test is not routinely carried out here in the UK. (The previous expert on this thread is based in the US where things may be done differently.)
Your symptoms, particularly the pain you describe, sound consistent with a condition called chronic prostatitis. This condition can also cause a rise in PSA.
This is a link to a UK website which tells you more about it: http://www.patient.co.uk/health/chronic-prostatitis
The type of pain you are describing is not usually associated with prostate cancer. In fact it is very rare for men to present with penile pain as an initial symptom of prostate cancer.
The urologist will obviously be able to examine you and give you a definitive answer as to your diagnosis. He (and not the GP) will organise any further tests he wants you to have. This may include analysis of fluid from the prostate and perhaps a scan of the prostate. CT scans with contrast and scanning of the bones would only be carried out if there was a clinical need and are not part of a routine "work up" here in the UK. The urologist will go down this route only if necessary and it is too soon to say you have to have these tests done as well.
I hope this goes some way to reassuring you. It is always wise to consider prostate cancer in ANY man with prostate symptoms but there are many other benign causes too. Your GP has quite rightly asked a urologist to see you but that is standard practice given your symptoms.
I wish you well and hope this is soon all resolved for you.