I am depressed

It snuck up on me. Over the last 24-48 hours I've been feeling awful mentally. But maybe awful is the wrong word for it - it's more like I don't feel much of anything yet am overwhelmed by emotion at the same time. This afternoon I even wondered why my life was worth continuing at all, the first time doing so in quite a while. Part of me is lonely, but the rest of me is resigned to that simply never changing - I'm neither tall enough nor good looking enough nor 'useful' enough for women to consider anything other than a threat regardless of what I do. I'm so tired... maybe sleeping forever wouldn't be so bad.