To study effectively... Pls find out your learning style and you are able to recall the most information . Use colours to underline important text. And to focus the maximum... I would suggest you to sit in well ventilated and lighted room. Have the book you want to study and nothing else apart from.that on table. And also before studying close your eyes and take few deep breaths concentrating on your breathing and study.. assign short break and recall time after certain amount of time.

Hi thanks for your approach. I appreciate that you are able to recognize improvement in your emotions.1) I am not sure you are completely able to understand the reason for depression, in which you still feel that you are not completely out of it, 2) you can work on your expectations related to your academic life, how much you are able to put efforts and the output of it. 3) is it that something you lack confidence in your studies.  Which depends on the way you are preparing for exams, just few days prior to examination, you can take a small test using the time limit. This will help you to know your level of preparation, time management and also confidence will increase. Take care stay positive. Good luck.