It just does not work to "sweep it under the rug". I hope you can find a good counselor who can help you lift the rug and get this issue out into the open. Just a few observations from my point of view as a prostate cancer surgery survivor:
1) It is normal for men to not "just be satisfied with a clean PSA". In most cases, sexual function is very important to men, whether or not they or their doctors talk about it. And if the patient doesn't talk about it, it can eat him up inside.
2) Sex following protatectomy often needs to be re-developed, almost from scratch. I don't have near the function I had preceding this operation, but with my doctor and girlfriend, I've developed a program for rehabilitating this important part of my life. I use a pump for maintaining length and erectile tissue, and injections for weekly intercourse. By the way, these injections have made for some amazing experiences, with erections that last for an hour, including after an orgasm. I'm still hoping to recover more natural erectile ability.
3) By making it safe for you and your partner to communicate about what's really going on here, intimacy can return, even if it doesn't specifically involve intercourse at first.
I hope you can get a conversation going.