Watermelon juice fast; feeling weak and shaky !?!

So I started a fast 2 days ago I am currently on my third day. I take a psyllium husk and Bentonite clay drink in the morning then 1 hour later I take a parasite drink then 1 hour later I have my juice that I'm fasting on which is organic Watermelon and organic lemon juiced in my juicer and I add a tad of cayenne pepper and 1tsp of black organic cherry concentrate juice. I have the Watermelon juice 6-8 x a day and he p&b drink and parasite drink again at night. It's not for weight loss, it's to cleanse my system as I'm dealing with an illness that I want to rid of which I believe is related to my large intestine, kidneys, liver, immune system and possibly lungs - basically my whole body system ! On the first two days I felt really depressed, I assumed this was just because I wasn't allowed to eat and possibly was a sign of die-off from the parasites. Today is the morning of the third day and I woke up feeling extremely dehydrated even though I have been making sure to drink 2L of water a day. I have since had my p&b shake not long until I have my parasite drink and I have also drunk some water yet I still feel shaky and weak, when I stand up I feel like I have to be quick with whatever it is I'm doing or I might collapse! Is this just toxins and what not being released from my body and making me feel this way? Will it pass afterwards if so? Or is my body telling me I need to eat? As I said it's only been 3 days and I plan to do this (no eating just Watermelon juice drink ) for another 4 days - 7 in total. I don't want to start eating because I feel the energy not being used to digest food is hopefully healing my organs that need healing. Thoughts ? Also low blood pressure runs in my family! I once had my blood pressure tested at the gym and it was low according to the gym instructor but they're not always accurate.