Sin, All the things you mentioned can help.

taking a week off can help - just go off and do something else, go to a club, go drinking, go to a couple of movies- just do stuff you don't often get teh chance to do. It can be hard to keep on training day in day out especially if you don't have a fight date to work towards.
Just think of it as taking some R&R to let your mind and body relax before starting up again.

Watching classic fights also helps get the fire back, especially if it's your favourite fighter. Ask your trainer what he thinks you need to improve one. Having someone you respect give positive feedback can be a great motivator.

As for what some of the others have said-only YOU know if the fight game is for you, when you are down just accept it as part of you, and you know you will come up again the on the other side of the depression, people just saying get over it don't know shit.