If you lost that much weight I wouldn't think it would be just water weight, maybe adding in weight training and protein will kickstart you again, that's what I'm planning to do myself.
I just got this book too a couple of days ago and so far the first 100 or so pages is very good and educational, diabetes runs in my family.

There's one section where they write that if you overeat but are doing LC, you won't lose weight but you won't gain it either. If that's true I'll enjoy maintenance!