How is Percy feeling in Chapter 9?

Percy is feeling miserable.

The next morning, Chiron moved me to cabin three.

I didn't have to share with anybody. I had plenty of room for all my stuff: the Minotaur's horn, one set of spare clothes, and a toiletry bag. I got to sit at my own dinner table, pick all my own activities, call "lights out" whenever I felt like it, and not listen to anybody else.

And I was absolutely miserable.