Someone recommended to me Composing a Life, by Mary Catherine Bateson. Bateson writes about her experience and four friends, focusing on how women since feminism have come to invent their lives as they go along. The recommendation came because I was talking about what I anticipate for my life as a result of John's illness and I said "It isn't who I expected to be."
Bateson's book does have a chapter on caregiving, but she focuses mostly on a very broad notion of caregiving that we do in the workplace and all sorts of settings, not just in the home. She emphasizes interdependence, complementarity, and collaboration (my first reaction is that doesn't do me much good with John).
There is something freeing about Bateson's notions of how life is more creative if it doesn't follow a linear path. And I'm thinking about her idea that parenting is an analogy for much of what we learn in maturity: "the willingness to relinquish control gradually and welcome the transition to an unknown future."