I see you've already gotten a lot of really excellent advice.
When I was diagnosed, my uro felt a palpable tumor on the left side during the DRE. He told us then that it was very likely the left nerve bundle could not be saved. He didn't "feel cancer in the nerves," but he knew from the location of the tumor that it would almost certainly be necessary to remove that left bundle to ensure that he "got it all."
Perhaps that's what your urologist was trying to say.
By the way, in spite of continuing ED, my wife and I have a very good sex life, and I am in no way less of a man than I was before. In fact, I would argue that I'm a better man than I used to be. Far from perfect, but better than before.
Good luck to you as you and your husband work your way through some difficult decisions.