I've been being held hostage as well for a little over a month while my AD goes through her latest episode. It seems to be coming to an end and I'm free to leave my home without fear that she will die if I'm not available. It's only been a couple of days. I literally just told her this morning that I might not be available when she calls later today and I successfully did not return 3 seemingly non-urgent phone calls from yesterday. I used the phrase "I have a life too". Selfish, selfish drug addicts.
I wish I knew what the answer is - sometimes I jump when she pulls the string, someimes I don't. I just take it on a case by case basis. One day at a time.