Dementia/Alzheimer's?

My grandmother refuses to talk to me. It's been a ten year process. She believes I live out of state in a town nearby her that I've been married since I was fifteen. I live states away from her and I've never been married. She is highly functional. She looks like there is nothing wrong with her. But ever since I was young and lived with her she always had created dissension with relatives. There is no talking with her. Now she lives by herself. I worry because I feel helpless to bridge the gap and she refuses to acknowledge the truth. Is there a book I can read to help me understand my experience?