I can pray for you.
On the one hand, the Church says masturbation may be a venial sin under certain circumstances (such as, being around your age).
On the other hand, I hesitate to even mention this because it is certainly not a free pass for masturbation.
Only God knows whether it is venial or mortal. He is the one who judges our hearts, and He knows our hearts better than we do.
Continue to go to confession with a contrite heart. Remember that God does love you even during these times, and He and His mother are hoping you will turn it around. Don’t begin to hate yourself.
Nevertheless, it is difficult to stop. I thought it would be impossible for me. Continue to pray, when you stumble try again and seek God with contrition. “If your right hand causes you to sin, cut it off!” Okay… so… obviously I’m not saying you should amputate ANY part of your body (the Church condemns this!!), but what I am saying is, stay away from things that tempt you. Put a password on your computer so you can’t access porn sites without entering it. Throw away any porn or other tempting materials you have. And stay busy.
God bless you, good luck. Above all, remember God loves you, do not hate yourself, and always keep God in your sight.
Edit: I was reading an article by a nun in a vocation magazine recently… she said, “…and let’s be honest, the sex drive does not go away entirely!” Don’t expect perfection in yourself; but do what you can to follow the ways of our God.