Help?

Does anyone know what this is? I'm experiencing a sensation like mental drag, or something. I do something, and then a second later my mind catches up to whatever my body just did, and it's almost like I can feel my brain turning inside my skull, trying to track stuff a second after my eyes have already moved. It's ... disconcerting. I'd think it was tiredness, except I slept close to sixteen hours last night, and this wasn't there earlier. Besides, it's nothing I've felt before when I was tired.

Anyone have any ideas? I'm confused, and more than a little disconcerted that every time I move my head, I feel my brain shift a second later. -_-;