Water Fasting But Not Losing Weight. Please Help!

Some weeks ago I decided to begin my first Water Fast in order to lose weight as well as cleanse my system.
In the first week I slimmed down a very noticeable amount, however the scales didn't show any difference until day 5, at which point it showed I had lost 10 lbs.
Since then it has been almost two weeks and the scales haven't budged at all. The pictures I have been taking weekly have also shown little to no difference aside from some minor weight-loss around my face.
I have remained very dedicated to the fast so far, having consumed nothing but water for 18 days now (around 2 litres a day), and although I have been less active than usual due to fatigue, I fail to see why I do not appear to be making progress.
If anybody can offer some advice or an explanation as to why I appear to have stopped losing weight? Tweet