Hi RawDeal, just wanted to say we may be twins :)
I had a rocky childhood - unstable due to divorce etc, which happened right around the time that I learned about nuclear war, some disturbing alleged paranormal phenomena, and the fact that Skylab was now defunct and about to fall out of the sky. I can clearly remember being aged 7 - 9 and lying in bed braced for impact / disaster.
It was a reaction to my home life being in total upheaval and the fact that my adults could apparently no longer give me security.
Periodically in times of personal stress I move perfectly realistic fears and anxieties onto fantastical ones because I was not "allowed" as a child, (and once particularly as an adult) to express my justified fears.
I am now in therapy for lots of reasons, but what you describe really resonated with me, and I wanted to try and reassure you that you are not alone. The trouble is, it seems, that when one learns an unhelpful way of dealing with stress, one sticks with it, because we have no "proof" that being logical or rational according to the rest of the world will help us, because we have no experience of it. It's a bit like children getting their only attention in a negative way, so they continually behave in "bad" ways, because "bad" attention is better than "no" attention.
We all need to be validated and not to be discounted - sorry for the "therapy" speak but if you wanted to google for support as well, these words would crop up. :)
The fact that you are sharing your thoughts and want to dismiss them shows you are changing already - but you say you are worried about your own future at present, and it is soooo hard to let go of the familiar even when we sort of know it's not helping us.
I hope you don't mind me posting, but I know how bad one can feel when you have fears and panics about things which other people don't seem to have - I think more people suffer silently than we may ever know!
And I just read the NASA article and was fascinated - didn't know the Mayans carried on their calender after all - must look at that some more! 