Unfortunately, waiting is part of the deal, and it can be one of the hardest parts. Test, wait; consult, wait; scan/biopsy, wait; treat, wait. And even at the far end there is the repeated wait for the next PSA check...
The underlying reality is that the cancer has been present for some considerable time, and you have lived with it quite happily. The big difference of course is that you now know about it, and you can't ignore that knowledge.
This is much easier said than done, but everyone here has been in the same place and - assuming that you are on a medical track in which you have confidence- the only thing you can genuinely control right now is how you feel about things. Carry on doing what you enjoy, and practice putting your concerns into a box. They won't go away but you can definitely get better at putting them into perspective.
Best of luck