Hello,
I have found myself to be engaging in a lot of day dreaming while I study for my exams in school... I kinda keep thinking and visualising incidents about the past, or make incidents which might happen in the future, and spend a lot of time wasting like this, thinking about nonsense. My focus while I study is totally low and my mind drifts away all the time when I study.... Which paralim can help me conquer this problem?

Thanks in advance
-HR