I don't know you, but I feel similarly. I think ambition drives us to stay up late and arise early. It's not a common trait in mankind I'm finding.

This may be silly, but are you keeping up with the basics? Do you make time to exercise? To write down your day in a journal? To recreate somehow daily? Simple things like this I've found are essential for my personal mental well-being.

Another point a prof taught me--take time to celebrate small accomplishments. Fix a particularly nasty bug? Go for a short walk, or shoot some hoops in the hallway trashcan. That way you aren't deluded with problems like a bad day of rain.

Good luck, friend.