Painful and over sensitive testicles

Of late I am feeling that my testicles are very sensitive and even some casual unknowing pat in my testicle leaves me writhing in pain. I also have this feeling that my testicles are shrinking. Two years back blood oozed out of my scrotum when I pinched a small boil on the scrotum and it was hard to control the flow of the blood... Is there any link between the two? What is the reason for my over-sensitive testicles? Please help....