I haven't seen these posted anywhere here (although maybe I just didn't look hard enough), so I thought I'd add some links...
These are blog posts from Allie Brosh, on her blog titled Hyperbole and a Half. I discovered her blog long after my own experiences with depression, but I think she's done a really amazing job of expressing what depression feels like. She doesn't really offer advice; but what she does offer is something you might be able to relate to, and some hope for the future, if you're feeling like life's meaning has slipped away from you.
Part One
Part Two
Just thought I'd share...