Oooof. That sucks. Been there. Had a hard drive fail about 7 years ago. We lost so many old family photos.
On my computer, I now have quadruple back-up!
1) I have an external drive that has a "clone" of the operating system, major applications, and important files. If my computer's internal hard drive fails, I can boot from this external and be back up and running immediately.
2) I have an external hard drive case that contains 2 drives (both 1.5TB) in a RAID 0 configuration, which means it looks like a single drive. Anything copied to it goes to both disks (which gives me 2 copies). I have an app that automatically (every morning at 2am) backs up any changed file. This set-up ensures that if a back-up drive fails, I pull one out of the case, replace it, and the twin drive then copies everything back over to the new one.
3) I use Carbonite off-line (cloud) back-up. Backs up slow all day long. I do this just in case there is any damage to my computer and back-up hard drives (fire, flood, hurricane, Gary Busey). For a measly $59 a year, it's weeeeeeeeell worth it.
It's not a matter of IF your hard drive(s) will fail, it's truly a matter of WHEN. Make back-ups!