Just read Lynn j's post, which made sad reading. Perhaps I can help a bit.
I had a radical prostatectomy when I was 59 - three months after being married for the second time. We had had a lovely sex life and were determined not to let it die but I had been left impotent - still am, now 62 - and injections weren't satisfactory (either didn't work or worked too well, and destroyed any spontaneity) but we did our best and I could still make love to my wife and give her orgasms (mainly through oral sex), and tried toys etc.
It wasn't the same and we both missed penetrative sex a lot and it did affect both our levels of desire etc but it was better than the alternative of giving up, and then probably both feeling unhappy at the situation.
So my advice would be to be open with each other about your feelings, to try to work out how to continue to give each other sexual pleasure - even if it is difficult and frustrating etc in terms of how you'd thought of sex before - it is very difficult for a man to feel adequate without erections - and to focus more on non-penis orientated things. You've got bodies, fingers, mouths, tongues etc.
I wish you good luck.