Look, I know how you feel. I'm a professional writer and journalist, and the digital files I save are pretty much the only result of my life's work, so I try to save them for the future. I'm in the same position, but I seem to have a system that works.
Amazingly, (or sadly, depending on your opinion) I also have all of the documents and material I've ever created (starting with the disks from my Apple //e from high school in the mid 80's, to my emails and my first book's Word files from the early 90's, and everything since including about 300GB of photos) still immediately accessible and viable. It comes from the following understanding:
Hard drives (or basically any storage medium) can and do fail, but they tend to do so in a predictable pattern, but rarely at the same time, so the key is duplication and regular maintenance.
For example, hard drives tend to have a 5-year lifespan, but two identical hard drives in two different machines aren't going to fail on the same day unless there's a fire or natural disaster that wipes out your room/building/city/whatever.
So what I do is have a system where your data is regularly backed up or duplicated at least two times to at least two devices, and then regularly check them. These days I use syncing software that copies my files to a second drive (internal or external - doesn't matter) and then to a second drive to another computer on the LAN. If the syncing software can't read the destination disk during the sync process, then I immediately know something's wrong with that disk, but it's no big deal to replace it and resync, because the chances of the original disk and the first duplicated filestore of both going bad in those couple of days is basically nil. The syncing happens every night. (And I know, I'm already up to three drives, but two drives would be fine, and drives are cheap anyways.)
Every few months or so, I grab a portable external drive from my office a few towns over and make a new copy of my files, and then return the portable drive. The chances of both all my home copies of my files AND the external drive at my office going bad at the same time is practically nil. And the chance of a major natural disaster destroying the disks at both locations is very remote too.
And then replace any drive that fails as the years pass. The new drives will be much bigger than the originals, allowing for more room for more data as the years pass.
Frankly, I think the notion of keeping digital data store that remains inert for decades is silly. You're always making new data. You (probably) always want it backed up. So the data store should always be changing. Once you accept that, and then accept a storage medium that allows for regular changing and updating, and then accept the need for duplication, then data storage isn't risky. Add automated software to do the syncing for you, and it isn't even troublesome.
(And what about those Apple // files, you ask? I have two working Apple //s I still play with to read the duplicated original disks. But those disks were also copied to a Compact Flash card, which I now use on the IIGS as a hard drive. The CF card is backed up to the PC, which an Apple II emulator reads just fine. The backup image of the CF card is always synced between the hard drives. I know, TMI.)