I feel you, I also unfortunately have experiences with that. It has profoundly changed my view on living, especially how I want to be treated when someday I'm heavily sick.

A family member in a coma takes a heavy toll on you, emotionally and financially. They are simultaneously there and not there. If they did not write down how they want to be treated you can never make a decision where you are sure what's right, or if they even want to be kept alive while not living. Eventually, when all your savings are burned through, when you might need to sell your house, you really wonder if that's what they wanted and if all that was worth it.

For me, the decision is clear: when I'm not able to make my own decisions turn everything off and let me die.