Ever hear of a book called the artists way? It a great book to work through it gives a guitar player alot of tools to use when blocked, or depressed. Also in times like that I go into my studio and lay tracks over a drum machine and allow myself to play poorly or well,..without thinking just doing it allowing myself to just go through the motions. For an hour or so, this keeps the chops up, I also call it fishing...fishing for the sake of fishing.