At this early stage and from what you have said I think the future looks very good.
Tip:
Don’t build yourself up to much, save that for him. The power of a positive attitude does wondrous things.
Yes, I do have experience.
Challenge him to a race up the steepest climb you know (when he’s ready).
A doctor once said to me serious illness is the loneliest time of your life. At the time I never really knew what he meant. Having been there I know now. Re-assure him constantly, plan for the future. Even make light of it if you can get away with it.
When you’re in that position you constantly think loved ones know more than you and pick-up on the slightest thing.
Good luck.