Are you scared that you can just die without warning? How do you cope with it?

Like right now, as you are reading this… doesn’t it bother you that right now you can just poof and die. I almost died a few months ago and It was extremely uncomfortable. My pulse was 279 and I had passed out in the doctors arms. They gave me a cold compress and wiped my forehead, and I felt wonderful, but still scared. I don’t know, how does one prepare for an unpredictable death so that it is as comfortable as possible?