Don't despair! It is absolutley perfectly and totally normal to feel like you want to hurl yourself off a bridge when doing these cleanses. It's just hard when you don't know that, and then it comes up and you feel awful and you think what a bummer that a cleanse makes you feel worse!
What may be happening is that the cleanse is stirring up all sorts of gunk in your body. I firmly believe that Depression is a disease of blockage and toxicity, so when stuff gets agitated, your system becomes temporarily overwhelmed with stirred up toxins and you feel worse.
But it's only temporary, and should go away as the cleanse progresses and then eventually you will feel better than you felt before. This has happened to me a few times. Just remember, it's the toxins, not you. Try to see it objectively.
Drinking lots and lots of water will help greatly. also, getting a colonic or doing a colema is of great benefit. Anything to help flush your body out, because you don't want the toxins hanging around and getting reabsorbed into your system. Then you will make yourself really sick.
Hang in there...good for you for taking charge of your health! Just know that this should pass soon and keep drinking pure, good quality water.