I can kinda understand. I have older parents, both with health issues so I think I know what you mean. You can never prepare for the loss of someone you love. Never. Like Tonja said, just dig every moment with them and make sure you tell them all those things you've meant to say or haven't said enough. Even if the situation doesn't happen for another twenty years, it'll make those twenty years all the better. It's something that I've been trying to do as well.