Move, Move, MOVE

That's what I keep telling myself. But I just cannot move. I stare down at my tiny legs, and say to myself, Just get up. Move. Move. MOVE. But I can't.
I haven't always been like this. I used to crave the burning feeling I got in my legs running or pushing myself up a steep hill on my bike. And I still do. I just can't.
It's not that easy to explain, simply spelled out. My mom says it's normal, my brother says it's lazy. But I think it's something else.
Everywhere I go, I feel as if the ground is trying to suck me into the gravel and devower (I didn't spell that right) me whole on the spot. I feel gray. But gray isn't always the same for all people. So I'll tell you what "gray" is to me. It's tired. I'm always tired, as if just keeping my eyes open is too much. I want to get better. I really do.
I blame it on school. I hate school. But I know I'll miss it. Why does that always happen to me?
Sorry for this post. I'm confused now.