Death is inevitable and I think it's a common thing to be afraid of. No one enjoys having those worries...I can't really pretend to know anything of loss except through my relationships with other people. Everyone has a story and every story has to come to an end at some point, but that doesn't mean that yours has to too. As far as worrying about the health of others (specifically loved ones) my dad lost his dad unexpected of a heart attack when he was around 11. So growing up it was always "you better appreciate me now b/c I won't be here forever" type of remarks I'd hear or "you'll know when you're older and I'm gone" So I grew up with the mindset that I have to enjoy my parents & the time I have with them. I'm not afraid of it, it's a natural part of life....but I'm not going to pretend that I wouldn't think about what he'd say or get upset.
"Though my soul may set in darkness, it will rise in perfect light;
I have loved the stars too fondly to be fearful of the night."