Blood Flow to Testicles/ Penis

[Deadly Viper]

When I wake up in the morning the blood in my penis and testicles slowly rushes away until it feels like there is not adequate bloodflow.  Often the tip of my penis is bluish and the shaft forms into an hourglass shape.  I feel discomfort in this area, and I also experience tiredness, fatigue, etc. Possibly because the function of distributing hormones throughout the body is disrupted.  
I am able to maintain an erection, and when I do, this seems to fix the problem.  The hourglass shape smooths out to a normal shape and after the erection subsides the flow is normal and the tiredness goes away.  The next morning, however, I wake up and it repeats again.  

A related problem is that after I have had an erection and it has gone back down again, and the flow to my testicles and penis feels normal, it is very uncomfortable to sit down.  I feel like I am sitting on, or squishing the veins that supply blood to the testicles/penis.  

If anyone has any information, or educated guesses, I would appreciated it.