Hello, people. I myself have struggled with this issue in the past in my life, and I will tell you that it is only by the grace of God and his faithfulness to be my strength when I am weak that I can tell you the good report that I am about to embark upon.
I've been where you are right now before (and where all but one other of my male companions in my youth group are right now) in my life, and let me tell you, Jesus is strong enough to defeat your battle for you, as long as you're willing to let him do it. I just turned 22yrs. old on July 26th, in the sexual pinnacle of my life, yet (again, it is all by the strength God has given me) it has been almost 1 year and 9 months (500+days!!!) that I have given in to masturbation or pornography. You want to know the secret to overcoming sexual lust? THERE IS NONE!
The devil is absolutely relentless with young guys when it comes to sexual impurity (can I see a show of hands if you know what I'm talking about!

). Erego, we as Christianis must be willing to be as equally relentless in our defence of our bodies and minds if we are ever going to conquer this desire. The key to overcoming masturbation (and everything else it entangles) is prayer, prayer, prayer, prayer, prayer, and MORE PRAYER!
Pray to God for deliverance from filthy thoughts the very second they enter your head (literally; it should be a knee-jerk reaction, if it isn't, make it become one!). Then when the thoughts come back 5 minutes later, pray again! When they come back again 3 minutes later, pray again! When they come back 12 minutes later, pray AGAIN! When they come back WHILE YOU'RE STILL PRAYING! KEEP ON PRAYING!!! Ask Jesus for strength over your fleshly indulgences. Ask him for liberation from the thoughts entering into your mind and plaguing you day and night! Come before him in all humbleness admitting that you cannot defeat it yourself (because, frankly, you can't (I know this because I know I STILL CAN'T MYSELF!), and trust in his omnipotence as your shield and sword to the enemies attacks! And above all! Never, never, never, never, NEVER let down your prayer as a counter-attack to sexual impurity. Don't ever think to yourself "Wow, this is working, it's been 3 days and I haven't given it to anyth... *woops*, here's another attack. Well, I've abstained for a bit now, I've got the whole prayer routine down now, I'm stronger than I was before, I can handle this one. Come on, devil. Give me your best shot..."! It's instant death!!! You'll find yourself right back where you started and feeling even more worse about your circumstances and weaknesses than you would have imagined after you've had some success. NEVER STOP PRAYING when temptation captures your heart! And always remember, the rest of the Body Of Christ is in the same boat you are. We're all wretched sinners saved by grace. We don't all have the same sin... (though many of us do), but we are supporting each other nevertheless. You are never alone in your struggles!
I pray (<-- no pun intended) this has been a blessing to you. God Bless you, bro!