First of all, each person has his own way of remembering things, do not compare yourself with the capability of others, secondly I would suggest you start playing games or exercising, whichever thing suits you best. Give yourself a quota, limit your study and play time according to your quota and you will automatically see the positive effect. Also when you study, try focusing on your studies, learn breathing techniques if your mind diverts in between. Wish you all the very best