I have extreme penis glans pain following surgery 2 months ago now healed. Could it be prostatitis?

Can anyone advise me at all? I visited my GP in December to check out a small dark red nodule on the tip of my glans penis in view of a recent ache in that region. I was supposedly referred to a dermitologist who diagnosed a slightly raised vein and immediately performed 'minor surgery' on me to remove it. Ever since I have been in more or less permanent excrutiating pain which the NHS hospital urologist says has nothing to do with the surgery! (Just a coincidence!?) A subsequent ultrasound scan showed up some constricted blood vessels which the urology doctor said was the cause of the pain (which does feel like my penis head is being strangled, and the base is going a dark purple colour which the urologist seems to think is perfectly normal!), but the urology consultant overuled him and denied this. Consequently the consultant has proposed my going back to my GP for referal to a pain specialist (just pain management?) but has also suggested a biopsy on the prostate, despite my having been told previously that I had no prostate problems. I have had a urine check and rectal examination and my prostate is a little large (I an 66) but firm. My PSA is low (a recent GP blood test was only 1.4) and an abdomen/pelvis scan and a cystoscopy revealed nothing. But could it be prostatitis (perhaps non-bacterial), which the doctor only seemed to consider when I asked about it? The urology consultant has put me off this by saying that a biopsy could make the condition and pain much worse (I am also on warfarin)and may not reveal anything or help with a cure, but that it is up to me! I know as well that there could be possible risk of side effects such as scarring of prostate tissue, bleeding and infection. So will a biposy definitely show if I have prostatitis (I have read that prostatitis can cause glans pain, and I have always experienced frequency of urination), and if so can it be treated?  (I have read e.g. about prostate massage and alpha-blockers)? And if only with anti-biotics, why can't they just prescribe them as a precaution without having to risk a biopsy, I wonder. Or are there other methods of detection? It is over 2 months now since the surgery on my glans and I am an daily severe pain and am at my wits end and do not know what to do, especially about the biopsy in view of what the urology consultant said and the apparent risks. If I do not have the biopsy the urology department will simply discharge me back to my GP since they say that my case is unique(!) and that there is nothing else they can do.