I don't want to waste my time and my parents money

i am a dropper. i just cant concentrate on my studies because of my breakup. since two years i have been living in a hostel(in class 11th and 12th) but didnt studied properly because of my relationship problems. but this time i dont want to waste my time i really want to study but the thoughts of my breakup disturbs me whenever i study. it breaks my concentration. everytime i open my book thoughts of his dishonesty, of my bad past or how much i got hurt comes to my mind. please tell me how should i concentrate on my studies. i dont want to waste my parents money anymore.