It sounds like you're looking for an excuse to stop working on the werewolf book. Doubt is certainly part of writing and we should always try to push past it, but I don't think your problem is entirely with this book, I think it has something to do with your new work schedule. I could be wrong, but from your last comment it looks like writing in general frustrates you. My advice would be to look at your lifestyle and see what changed. Try to figure out what's frustrating you and adapt the old writing rituals to fit the new schedule. Also, it might just be that the werewolf story isn't as relevant to you as when you started writing it. I've had this happen a number of times, where I started off with a good premise, but then along the way the characters/situations lost my interest. I guess there were just things I needed to say and I couldn't say them with those stories.

But if this is just a typical rut, try to think back to what sparked your interest in the first place. Was it a particular character? The setting? The tone? Whatever it was, write/work on a scene that includes it. If your interest isn't restored, then maybe it is time to move on.

-RC