Having some anxiety is normal, in my opinion.
From looking at your husband's biopsy results, he has a great chance of being completely free of prostate cancer after his surgery, so that should give him some comfort.
The waiting is difficult...but once I made the decision about form of treatment, I felt better.
As a precaution, I typed up instructions for a memorial service, including a list of songs to be sung (I love listening to music) and told a good friend where those instructions could be found on my home computer. Did not want to upset my wife by telling her about this. Felt better to have this done a couple of weeks before surgery.
I prayed for peace and strength and those prayers were answered. The last 3 to 5 days before surgery I was calm and ready for whatever was to come, realizing that with my high PSA and Gleason score even a successful surgery might yield a discouraging post-op pathology report.
My wife, my sister and 3 long-time friends were in the pre-op room with me, which was a great source of comfort. At least I knew my wife had close family and friends there to give her comfort while she waited. I was as ready as ready could be.....then came the anesthesia, then came sleep and a few hours later I was awake.
Tell him to take some long walks every day. The exercise is good for him. And lots of deep breaths. Tell him to do some kegels before surgery. It might help recovery on that front. And tell him to have as positive an attitude as possible. He has a journey ahead of him and needs to face it head on and with an optimistic outlook.
Best wishes to both of you during this time.