That's Ok...sounds normal, tbh. That's the weird thing about a terminal illness, or one that could become terminal. You do get the initial huge shock, that it's even possible your loved one could die. That takes quite some getting used to.
Then things kind of settle a bit, then the next shock is not quite so shocking...things carry on almost in reverse order. All this time, part of your brain is getting itself around the fact that the person may not be a permanent fixture in your future life.
You will kind of have moments of stark realisation, then go back to the semi-denial state for a bit longer, it just carries on like that really.
And oftentimes, when somebody does finally pass, the ones left behind feel almost as though they don't react in the correct way, or the way they would expect.
It's because some of the grief has already been managed. You might feel awful at the moment, but I don't think that means you will feel worse than this afterwards...if that makes sense. It's as though you are pre-grieving a bit. I think that's the proper name for it. So after the event you might not actually have a huge shock of grief to deal with.
the human mind is a wonderfully resourceful thing.