This is going to sound like a crazy leap, but it really isn't.
At it's core, Darwinism, as I understand it, says that the fittest organisms outlast lesser-fit organisms. I think of this as a consequence of change, in the sense that: all things are changing, but some change at slower rates than others; those that change slower appear to persist longer, and we call those the most "fit." We see Darwinism in all aspects of life, not just biology (cultural Darwinism). A fashion trend is a good example. You could say that all trends are disappearing (or changing) but at different rates, depending on how well-equipped they are to survive (criticism, competition, etc.).
The idea that the world is continually changing, or disappearing, has been expressed in (drumroll) Buddhism as the concept of impermanence. In Buddhism, from what I understand, the "law" of impermanence permeates all matter, including the self, and the individual is encouraged to see that even the self ("me, mippus") is something that is impermanent, changing, and disappearing. When one truly sees and accepts that, I suspect that many of your philosophical itches would be scratched.
Alternatively, and perhaps a little less abstractly, this book seems to be exactly what you're looking for.