I am not studying. haven't studied anything since last 2 years

I know the basics of all chapters of pcm. have studied some chapters but 85% syllabus is incomplete and still I am not studying. idk why. not getting a single fear of getting failed. parents asks me daily about"how's my study going ?" and I say them that's its fantastic. planing to start every month and still nothing happens. I want and have to achieve 80%> in my exams.

how can I ?

or can I ?