How can I concentrate on my studies and combat distractions?

Q: I am a 17 years old high school student. I am in class 11, science stream. I had a good academic record with 93% in board examinations and I always enjoy analytical and practical way of studies. My teachers and parents consider me as an intelligent boy and I too know that I can score well in future. But I am unable to concentrate on my studies for long. Though with a few hours of studies I do well. Nowadays I am really trying hard to study and I realise that I have to work hard to make a bright career. I try to involve my mind totally into it, but can't. I have a girlfriend and we talk regularly for half an hour. I don't think about her all day but I have 10% of her thoughts in my mind. I am also addicted to the Internet. Whenever I am free and feel bored, I play games or chat and waste many hours. I also masturbate sometimes. Will all these things affect my mind and studies? How can I cope up with these situations? Please don't tell me to ignore my girlfriend. How can I get back to studies and enjoy my relationship with her at the same time?

A:Certainly distractions can make it difficult to study - some things which might help:-1. Set aside a time of day to study school related material - during this time make sure you are away from your computer and take away any other material from your study area/you might want to switch off your phone as well.2. Preferably start with something which interest you3. Remember it helps to focus on one aspect at a timeOther aspects that you were concerned about - masturbation is common and is not harmful.