Recently lost several chapters of a story I was working on after accidentally pouring water on a laptop (goodbye hard drive). Lesson learned and I'm storing art in Stash or Google Docs going forward.
A couple of ideas that keep me from worrying too much about what I've written. A writer I know explained she doesn't worry too much about losing a page or two that she wrote because it will "basically turn out the same if I write it again". More philosophically, in The Master and The Margarita, Bulgakov wrote that "manuscripts don't burn."