Janie, you are a remarkable woman. If it does happen in your life I think you will be just fine.
A woman I knew - although not well - told me that she and her doctor recognized incipient signs of early Alzheimer's and she promptly made her plans and put them into motion.
First, she sold her house in Juneau and moved back to Anchorage where all her long-time friends live; she wanted a strong support group. Then she started writing down every important thing she wanted to remember, whether it was the name of the first dog she had loved to where her bank information was. She said that she will continue to do that as long as she can remember to do it.
She wrote down poems that she has always loved - and the reasons for it.
She recorded herself in conversation and in recitations - as she said, she didn't want to forget how she used to sound.
And more. The neat part is that she was happy; her spirit was as vital as I had always known her to be.
(That was about 6 years ago. Two years ago she re-married.)