Hi Belgz,He's probably very frightened. If and when he starts talking again (and I believe he needs time to process whatever information he received) remember all the psychological issues that goes along with someone discovering that they may have cancer (I don't know if that's what he has, only he can reveal what the issue is), especially when it affects the genital area or the breasts.
If it's cancer, a lot of people still think that cancer is a death sentence, but in our generation cancer is NOT A DEATH SENTENCE ANYMORE. Especially Prostate Cancer. Prostate Cancer is now one of the most curable cancers of all.
Venus also rules "relating" and "socializing", not just in terms of "romantic relationships" so his ability to relate to you and everyone else may also be wounded right now. His sense of beauty (even male beauty is ruled by Venus) may also be wounded right now. He really needs to be given the time he needs to process. Let him know that you're there for him, but allow him the space to process whatever scary news he may have received.
The fact that he has seen a doctor about this and had the tests suggests that he really does care about his health and will be committed to getting better.
I just looked at your post again and saw that Venus also rules his 7th House, so I will emphasize again that his ability and desire to socialize in any way, shape or form may be also feel very wounded to him.
I feel optimistic about whatever his prognosis might be. Give him time and if it is cancer, just remember, prostate cancer is one of the most curable and treatable forms of cancer.
God bless you and your friend, I hope he moves through the fearful phase quickly.