Hi there, thank you for posting your question on Ehealthforum. This is not intended as a substitute to visiting your own doctor.
You say that you have been to a urologist and a doctor many times and that they "don't know" what is causing your testicles to be so hard and to be apparently shrinking. With respect, I do not think that that is what they are saying. What they are far more likely to have said is that there is no condition or disease that they know of that can bring about these symptoms of hardness and shrinking of your testicles. Certainly, as a general practitioner of some thirty years, that would be my position about it.
Varicocele is benign abnormality that generally does not cause any problems.
Dr Andrew Rynne.
www.andrewrynne.com