Being cagey isn't a bad thing. People react quite differently and some are able to have a lot of treatment. Perhaps if he won't see you he is expecting it to have an effect that will last beyond the treatment. If he was seeing you and taking a risk it could mean he doesn't expect to last. That is a bit positive.
Does he have home helps or nurses. You might ask what precautions they are taking that lets them go in but not you.
It's not easy to offer much advice with very little information as there are a lot of reasons things may be as they are. Perhaps you will slowly reconcile more with the situation or perhaps think of something. You could ask a charity for advice such as the Prostate Cancer UK nurses or Macmillan.