Hi:
are you sure your bowels are moving well. Are you compeltely evacuating. from my humble experience, a lot of 'Chronic fatigue syndrome' symptoms are directly connected with bowel not emptying well. I have had these days, and realised I am not evacuating completely.
I have never had experience with P&B shakes. ( Also am hesistant to try it for certain reasons). But a week ago, I tried doing SWF (Salt-Water-Flush) and it worked very well. You can find my post about it. And when intestines are clean, energy levels are higher.
Try increasing the amount of Salt, if you get bloated by 2 tsp of salt. ( I use 1 tbsp). And once the eliminations start, I start drinking plenty of plain water. I big glass for every elimination. Till I am passing clear liquid.
I am now doing SWFing alternate days and will eventually taper it down to once a week. I noticed that its not habit forming and days when I did not take it, I still had a BM. I learnt that Keeping the intestines clean is very important to have more energy. And of course keep flushing and take those 'stones' out.
good luck.