It sounds to me that your husband feels shame and failure at not being able ‘to be a man’.
Too many of us - especially the alphas among us - equate sexual prowess with virility, manliness and ‘self’.
It’s a tough nut to crack if he’s unreceptive to talking about it; but you mention an upcoming appointment so please speak up at that meeting and try to steer a course toward healing both his physical and emotional selves.
But be prepared for pushback. I myself stare daggers at my wife or do the old eye roll when she asks our doctor a really pertinent question about my treatment; I feel like a little kid with his Mommy asking the questions for him. But I am always glad afterward that she broached a particular subject since my pride would never allow me to ask for myself. Be strong,
Phil