It certainly isnt normal to sit in a room with no lights on and it most definatly is NOTHING to do with you or what you have done to him, there is somthing wrong with the poor man by the sounds of it and maybe it would help if he saw a Dr.

Dont take it on as your fault cos it sounds more like depression to me rather than annoyed at a child.

Hugs and I truly hope things settle down in your house with you and your dad.