Thanks for your query.
In old age men usually have shrunken testes, it is not a thing to be worried about. The problem that needs to be addressed is your raised PSA levels. Usually it suggests prostatic cancer with help of other physical findings. There are many other conditions which may show raised PSA like Benign Prostatic Hyperplasia
(inflamed prostrate) etc
Negative biopsies do not always rule out prostate cancer
and further biopsies may be needed if your PSA remains raised or increases with time. you may need further blood test
to measure the free/total PSA ratio (FTR).
Visit your concerned doctor, reevaluate PSA levels and biopsies and rule out other conditions.
Note: avoid any sexual activity for at least a couple of days before your PSA blood test, as it may raise PSA levels.
Hope it helps.