Basically the opposite feeling of being energetic, perky and uplifted. It's when you feel empty, unmotivated, aimless and kind of hopeless, and still you're kinda desperate to feel better.
I just woke up and I feel it again.
Help me, I feel like I can't do anything.
As someone who MUST be doing something at any point this is the most calmly frustrating thing I could possibly experience.