Wow....this is such a painful story. I wish we could be there in person for you
Well, as you said, your energy is best spent staying here in the moment. Fretting about what the future holds is a waste. You know this but I will say it anyway...use the energy you have to stay healthy, calm and centered. Practice acceptance. Talk to your HP.
It does sound like he's getting good medical care -- you can be grateful for that if nothing else.
((((Hugs))))