Around this time, most people are gearing uup for their Boards and Mains. And it so happpens, that I have not been doing well in the test series. I feel low. What should I do?

Solution is right here.
http://www.askiitians.com/online-study-packages.aspx

Give more papers and based on concepts that you are weak in follow the above link for referring to those chapters.
Now is the time to give more and more papers rather than focussing on books.