Alexandra, Beware Dr Google. The more you read the unhappier you may become. You should focus on the PSA trend, which is remarkably good. These days there are lots of treatment options if the HT should fail. At 75, my age next month, he may well die, as we all must, with the disease rather than of it. I would plan for and make the most of your years together and shove those negative thoughts into the bin. They don't help!
Good Luck
AC