I overcame my depression, when I was in my 12th class (2008). The worst phase were the first three to four months. I gave my board exams through it.
I will not say out the reasons for it explicitly, for they are very embarrassing but I can tell you this, that I started believing something, which I wasnt. (a bit confusing, I know) It was horrible and draining, dealing with it everyday.
Positive reinforcements worked. A lot. So did, meditation. That is when I got into the habit of it.
You would say,that I should have consulted a psychologist but due to the very same reasons give prior I didnt want to.
Slowly, I got over it ( took me more than a year ), I saw I had grown through it and that was good.