Dear Patient, Thank you very much for your question. I want to tell that masturbation is completely harmless, innocent and physiological act practiced by both males and females. Also an Australian study has showed that people who practice masturbation often when they are young are less prone to prostate cancer in older ages. Therefore, there is nothing to worry about your masturbation unless it disturbs your studies, work or other important daily activities. If masturbation disturbs you concentrating on other work , then it can be a compulsion due to an anxiety disorder called OCD which can be treated by CBT or prescribing anti anxiety medication such as selective serotonin reuptake inhibitors. About your penis size, I am sure that it is absolutely normal. Most men worry about size of their sexual organs and it is another sign of anxiety. Also masturbation do not affect your production of semen. Do not think about premature ejaculation now. I am sure you do not have it, though, your questions show me that you have an anxiety disorder. I recommend you to see your family doctor and treat your anxiety. Anxiety makes people to constantly worry about things for nothing. I hope that I answered your question. If you have more questions, please let me know. Good Luck! Dr. Dinesh Nuwan Weerasinghe. MD