Thank you for your question. You are correct in that your masturbation technique is most likely the cause of the problem you are experiencing. Its not the frequency of masturbation but how you practice that has resulted in your experience. If you were to give yourself plenty of time, reflex, enjoy the sensation without hurrying, do pelvic floor exercises and practice delaying by few seconds every time, you will find that gradually you can prolong the erection as well as delay the ejaculation. The fact is most men masturbate to enjoy the sensation of ejaculation. When they do so they are in fact practicing to ejaculate quickly. So when attempting intercourse that is exactly what happens. So you will need to unlearn ejaculating quickly for pleasure and relearn getting aroused for pleasure of the sensation of arousal itself. You can learn more detailed techniques in 'managing premature ejaculation' by Metz and McCarthy. There are medicines available on prescription from a psychiatrist but I would suggest you try without medicines first and only opt for them as second line to support your new technique. All medicines have some side effects and if you can manage without them it will be so much better. hope this helps