Cant conenctrate on my studiess..

Join a sports group or some other extra circular activity, maybe it will take your mind off it.

Yes, the solution is that you masturbate less - for example, maybe you commit to do it once after you go to bed and never any other time or place. If you cannot restrict it in this way, you have an obsessive behavior, so that's why people are suggesting you see a doctor. It might be embarassing, but part of becoming a grown man is learning to take care of your health, mental and physical, and including sexual health and behavioral health. You don't have to tell your parents why you are having trouble concentrating - you can talk to the doctor about that privately - just your parents you are having trouble concentrating and would like to talk to a doctor about that problem.