Does anyone know the name of this book? It's a story about a teen boy being abuse by the stepfather more details...

It starts off kind of strange with the kid narrating and he’s saying things like I’m in my room, but I’m not in my room, they only think I’m in my room and he goes on like that contradicting himself for a while. Then at the end he gets beaten so badly he has to have all his teeth redone and is in the hospital. I read this when I was younger and that’s all I remember from it.