Hello. This is a common concern at your age, and feelings of shame and guilt are usual accompaniments. It is rather a physiological phenomenon, seen in even animal species. So its completely natural and not a sin! Also, detailed studies have failed to prove equivocally that masturbation causes long term ill effects on physical health. However, it might cause some ill effects on mental health, like feelings of guilt, anxiety, depression and subsequently loss of concentration, fatigue etc. So in your best interest, you need to have a control on this behavior. You can cultivate hobbies to keep yourself busy with and keep yourself distracted. You can try free hand exercises, yoga or some relaxation techniques like sports or music. If you still face difficulty, visit a psychiatrist. All these techniques will be taught to you in a professional manner, and will surely help you. In the meantime, eat fresh and stay well. Hope this helps. Dr A Rao Kavoor