On a water fast you do tend to loose your energy quicker than if you were to do a juice fast if you can try taking cat naps during the day it may help a little with that. The reason you haven't seen the scale move is because when you walk or jog you gain muscle and that out weighs the fat so as your burning the calories and loosing fat your gaining lean muscle mass and it'll take your body a week or so to adjust from the change in diet. Next week or the week after you'll notice a huge change in the scale so don't get discouraged your doing really good and by next week the scale will show you trust me keep on walking.( Also adding some strength training or maybe some pilate's would be a major help in seeing the scale) But don't get discouraged believe me it will work.