You know what you described is pretty much what I've been doing. I try juice fast for a couple days but suddenly binge eat. Juice fasting is NOT easy. I think stress can be a big part of the breaking the fast & eating for me or that may just be a excuse I don't know. I get these SUPER bad Sugar cravings which I know are caused by the yeast & bad bacteria in my body. I get extrememly weak/lethargic like you when I start juicing & I have a 2 yr old son & 6 yr old daughter to care for =(
I get like you to being emotionally miserable but again I believe & know its the Sugar addiction I have & all these toxins built up in my body.
I really need to try juice fast/feast for at least 30 days & stick to it. I'm hoping it will really help heal my pancreatitis. I'm like you to afraid of loosing to much weight. Today was my 1st day of my juice fast. So hopefully tomorrow will be day 2.
Don't give up if you fail just try again until you suceed.