Hi, I need super suggestions to control my heart…?

It is because of lack of concentration you are unable to control yourself. First you have to prioritise your work and then attend to it. You should know which is important - sleep or exam. Certainly everybody will say exam. You do not seem to give importance to exam. If you start doing meditation under somebody's guidance, certainly you will gain confidence, concentration , patience , good sleep and tension free day . Further you can do breathing exercise , thereby you get more oxygene to your brain. This is the only way by which you can overcome your problem.