Oh Diane, my heart goes out to you! Having been most recently a patient, but formerly a caretaker, I know exactly the stresses and emotional toll with which you are dealing. Try to find a few minutes each day just for yourself, whether a walk around the block, or listening to some favorite music. A time/place where you can let go of your heavy-duty responsibilities for just a short while. And please know that while there are no easy answers, you can come here anytime to vent or let loose, and there are many, many of us who understand exactly.
Joanna