Take it one step at a time Bill, i'm sure you'll find a way to deal with this somehow. Your faith and the love for your dad will get you through all this, i'm sure.
In the beginning it's so much of a shock, and you hear so many horrible things about Alzheimers that you always assume the worstcase scenario. My grandmother has Altzheimers (she's 86 now), and it was really difficult in the beginning (esspecialy for my father who was also battlling cancer at that time).
But the truth is, it's often a slow process and there isn't much suffering involved for the person who has it. When it starts out it may puzzle them why they can't remember stuff, but later they kinda get used to this. Some Altzheimer patients seem pretty happy and cheerfull to me when I see them in the place my grandmother lives.
I'll tell you this, my grandmother was always a bit of a neurotic. She constanly worried about stuff when she was younger. Stuff like bills, finances, her kids, gossip, everything always got to her and she was too neurotic to ever sit back and enjoy life. Now when I go visit her, it takes her a while to figure out who I am, but for the first time in her life she's actually happy and relaxed.
She can't do many things by herself anymore, but she's taken care of really well. And she can still play the piano!
Goodluck with your father, i'm sure you and your family will get trough this.
Ivar