You are depressed because your brain is not functioning correctly. Basically this is due to nutritional deficiencies and toxic overload -- although the situation appears very complex, addressing the problems of nutrition and toxicity will help your body to fix whatever is causing you to be depressed.
The challenge for you will be to choose the correct method of restoring your health. Most systems of healing do not work that well and cause other problems later on. At this time, I can only recommend that you begin a Nutritional Balancing program immediately. http://drlwilson.com/do%20hair%20analysis.htm It really works.