That is soooo annoying. It has happened to me and now I back everything onto disks and onto a CD or flash memory stick (just to be sure!). It takes so much emotional energy to write a story, I don't blame you for feeling you can't re-write it.
I have a few on the go (as you know!) and I pick up the ones which suit the mood I am in when I want to write. My mood has to be right or I can't write at all. I lost a story ages ago and couldn't remember anything apart from the 'tone' of it. :rollin Needless to say I didn't try and reconstruct it!
Remember : Your focus determines your reality -- Qui-Gon Jinn