Hii

This is a common Problem for many students, There are two solutions which You have. First one is that if You don't have access to any important or Useful information through Whats app like something which will cost You something if You miss that information then You can uninstall Whatsapp till Your exams this is the best solution, UnInstall You may find difficulty But soon You will be able to adjust.

other way is to Turn off all the Notifiacation so that You did not get distrurbed whenever a Notification appears, Or else You may switch off Your Mobile data and Decide a fixed amound of time dedicated to extra activities so that By that You can check Your whats app.

Some additiona tips is that Leave those Groups which are Not Useful and Just distyrurbing In that it will Not only distarct You but You will be find Internal Piece and will abl to focus moe on studies.