Looking back on this thread and having thought about for weeks now, I just want to make some observations.
First, Hayley just gave you a different way of looking at this thing. I think that's valuable.
Second, of all the comments made, the best in my opinion came from Marques who got it from Ray. Are you 100% sure you are ashamed of this?
Third, there's not a kid or young adult that gets through adolescence or young adulthood without succumbing to this curiosity, lust and release. And as best I've read these comments, there isn't an 'older man' who isn't still trying to flee this youthful lust. If any of us had a sure-fire 'method' to save you from the way God has created almost all of us, then I think you would have heard of it by now.
Since none of us has, then please don't ask us to behave like Pharisees and tell you to do something that 'we' don't or can't (or didn't or couldn't at your age).
If this (especially masturbation) was the worst sin possiible, then I'm at a loss to explain why it isn't more clearly spelled out in scripture. No doubt it is a challenge both to our flesh and to our spirits, and to our FAITH, most of all. But I think to "think" wrongly about it does more damage than the act itself. That's MY testimony. We are designed to fail, to look to God for all of our salvations, and to be humbled. Are you 100% sure you are 'humbled' by this? I spent considerable time in self-condemnation for my inablity to change my leopard spots and ethiopian skin. That's not faith. Whatever it IS, it's not faith.
Do the best you can. Confess your sins as they happen. Don't add to your sins faithlessness or pride (my sin is greater than God's forgiveness--who's is?-- or my effort is greater than God's sovereignty). This will end when you have learned every necessary lesson from it. Fear Him that He does not require too much of you. Learn them as quickly as you can.
I'm going to lock the thread at this point, something we've considered weeks ago. It's been a good one and I'm thankful for everyone's spirit in answering.