your not the only one, ive had that happen to my multiple times. yea it sucks and you kick yourself in the ass for a few days but eventually you get over it. and yea backups are your friend
the only thing right now i dont have backed up are my movies cuz its like 50+gb of stuff and i dont feel like burning 12 or so dvds right now... heres sumthin i used to do, make one drive just for storage and when you go to reformat/reinstall something, unplug the storage drive
works like a charm everytime, that is until the storage drive dies unexpectedly
(had that happen atleast once too, my 80gb DM +9 which was my main drive died unexpectly while i was swapping MoBos)