Dear service user, thank you for contacting Healthcaremagic. I have gone through your question and understand your concerns. You told that you masturbate for last 12 years (since the age of 14). Let me tell you young friend that there is no such thing as excessive masturbation or over-masturbation. Just as excess of sexual intercourse cannot lead to weakness, so also excess of masturbation. This is a natural activity and I would say a healthy activity and does not either affect or deter sexual performance. Masturbation causes impotency is a rampant myth. It is one s worry about semen loss leads to insufficient erections. So, just relax and enjoy pleasurable sensation during masturbation. Do not focus on size and your performance during masturbation. Masturbation is (in fantasy) sex with someone you really love! The width and length of penis vary from one individual to another. The normal length of vagina is about six inches. Only outer one third and the front wall of vagina have nerve fibers and hence sensitive to stimulation. Rest of inner two third is largely insensitive. So if you want to arouse your partner during sex, you should focus on the areas of maximum nerve endings hence clitoris and inner lips or labia minora, the outer wall and outer two third of vagina. So for female sexual gratification, the size of erect penis could be anything from two inches or more! You remember that what is important is strength and not the length! Penile entry followed by to and fro continuous movements is adequate. It is men s technique, not his penis size that characterizes the lover in him. Bigger is better is Godzilla logic. Hope I have answered your question. If you have any further questions I will be happy to help. Wish you good health.