These essays and articles may give you some ideas on how to deal with healing crisises (the lows) and explains the beautiful highs and peaks of juice fasting.
There are also articles portraying the benefits and healing properties of the common fruits and veggies we usually juice. By being informed you can tailor your juice fast to your health needs.
If you have a foggy brain, I would think it's either toxins passing through your blood stream on their way out, and/or, you need to cleanse your bowels. There are many ways to do that, enemas, lax teas, psyllium and clay cleansers, fiber cleansers and Oxy Powder (www.oxypowder.com) There will be many times you have toxins moving through your system while on this fast. When you're feeling badly on a juice fast, I would suggest to drink more juices (with lots of greens!), lots more filtered/distilled water and to rest your body until the crisis passes and it WILL pass. You just have to wait it out.
I agree with Julie... please start a blog. There will be many people coming in after you who will need your support and would benefit highly by following you on your journey to better health. You have much to share.