Urethral pain

[miclus]

I have this constant pain in my penis/urethra, that seems to run all along the underside of my penis and into the right groin.  It's just a constant irritation pain, that is always there like a pressure.  My lower back burns a lot when sitting and my buttocks hurt.  Urological workup has revealed nothing.  I've had these symptoms for 2 years now.  The pain is permanent, and never goes away.  It causes voiding difficulties sometimes, where it appears like my muscles are already squeezed when using the bathroom, and makes it seem like my urethra is already closed off a bit, making it hard to get out sometimes.  Same with bowel movements.  Feels like my butt is already squeezing before even using the bathroom.  Feels like I'm permanently in this state and no resolve.  I've had most urological tests you can have except direct view of my urethra, but I feel the fact that I can urinate ok many times pretty much rules out a blockage.  I had a bunch of blood work too and a colonoscopy.  The symptoms came on one day about 2 years ago and the first symptoms were severe burning in my back and buttocks, almost like they were going numb if I sat down or leaned against something.  But, with nothing touching them, like standing up, the burning would stop.  It was akin to a sunburn I might say.  

Anyway, these symptoms are so bizaare.  Could it be neuromuscular in origin?