Having been through almost 4 years of this "mysterious stuff", I can tell you from experience that when your body starts to get rid of toxins you don't feel good at all. I used to feel like I had the flu all the time (except no fever). My detoxing began with homeopathy, then continued with other "cleanses". It's kind of like opening a can of worms for a while, once you start detoxing, toxins just keep "coming out"...and your body responds. I wish I would have had this forum 4 years ago because the worst part about all of it is the feeling of being alone. The doctors have no clue about this type of thing. If you don't fit into their tests, they're lost.
I can also tell you that when I felt the worst, the thing that helped me the most was colonics. Now I was not a big fan of something like this when my chiropractor at the time suggested it, but I was feeling so bad I was willing to try anything. I'm glad I did. I have not experimented with natural colon cleansers, but am looking into the Awareness products as well.
Either way, when you're really feeling bad, I think it's due to a buildup of toxic sludge in the colon and anything that will help remove that should help you feel better.
Hang in there...it will get better...and you'll feel better than you could ever imagine.