It's curious but I'm the opposite. I often (not always) wake up full of beans but gradually crumble into crapitude as the day progresses. By mid-evening, I want to hibernate and start fantasising about sleeping for a week, except I'm actually a very poor sleeper. I think it must be harder to always wake up feeling like crap, though - I feel for you.
Today was a much better day I think, still had some crappy parts, but yeah, more happy moments.