Men in general don't show emotion well. I had 3 sons who outwardly showed nothing. I only knew of their fears by friends, when drunk...or in my youngest son...factitious illness to not go to school in case something happened...I don't actually think he was consciously aware of that. Young men are really clever at burying fears...sticking heads in sand and pretending it's all okay. It doesn't mean they aren't fearful of what might happen to you. Young men have high suicide rates because of deep emotions that they don't have the skill to deal with...and after the event...most people would say...I never knew they were even depressed.
So...don't think he doesn't love you. Don't think by keeping busy and distracted doesn't mean he doesn't care. His personal life experience is limited, he probably has limited understanding of living with a life threatening illness or even chronic disease. It hurts yes. But just take his "carrying on as normal" as a son who is strong and resilient and doing what he needs to, to cope.
Kath. X