Final Exam arrive soon

Final exam only left around 19 days and I still haven’t start my revision yet. I don’t know why I still don’t have any mood for study. I always have a plan to study in my mind however every time I don’t do it. I always find a reason that I need finish my assignment first but every time I do my assignment until half I go to play Facebook games, watch videos and others. God, please help me so that I will start my revision tonight or tomorrow.