Day 8 -- Bodily funtions are strange

I have juice fasted for a week before, but decided to Water Fast to cleanse myself and drop 15 pounds (I'm 120, but my normal weight is 105. I am very small.) So it is day 8 and the fast has gone well, for the most part. I had TERRIBLE back and leg pain for a few days, but someone told me that is due to toxins. Then on days 6 and 7 I felt fine, except when I got up. I would be dizzy. Also on days 6 and 7 I, for the first time, passed a dark, liquid stool. It was NOT like a normal bowl movement or diarrhea. Was it the toxins being released? Also my urine is a dark yellowish-brown. Is that the sign of toxic release too? As for the weight, I have only lost 5 pounds!!! That is so strange b/c on my juice fast I lost about 10 pounds in 7 days.

My goal is to go a full 2 weeks with this Water Fast then juice for a week before going back to a normal diet.

Thanks friends.