Surprisingly, or perhaps not, this is all about our spiritual growth. Ultimately this is a spiritual journey. But the truth is you can stop masturbating right now.
Avoiding temptation: The Lord's prayer says "Lead us not into temptation." For me, a big challenge is to avoid lust in general. That means staying away from TV, and racy scenes in movies or on YouTube, and of course, no porn or anything like that. It means maintaining "soft eyes" at malls, looking generally downward instead of checking out the "sights." It means not glancing at people's sexual organs when you see them or meet them. It means looking away from provocative billboards. It means not spending time alone in a closed environment with someone of the opposite sex (or someone you are sexually attracted to). It means reciting a prayer whenever I feel a temptation. It's called the shield prayer, which can be used dozens of times a day:
"Lord come into this temptation, please remove any desire to look or fantasize in this situation."
PRAY THE ROSARY!
Surrender your life to God: Honestly, without God, it's impossible. But for God, all things are possible. With a surrender to God, you can do it. I have, one day at a time.
Get into an accountability group: If you can't find one, start one. Find someone with the same ideas and make daily phone calls. This breaks a habit of isolation. Getting honest with others who are sympathetic will really help. If you don't have one, we started one.
Confession: For Catholics, it starts with making confession. For Evangelicals I would say talk to your pastor, but unfortunately most pastors these days don't understand the seriousness of it.
Restitution: Cleaning up every aspect of our lives. Returning stolen things, paying off old debts, stop cheating on taxes, making apologies to people I've hurt, stop cheating on work hours etc...
Eliminating selfishness: and dishonesty and trying to help others, particularly others with the same problem.
Prayer and meditation: Spending a lot of time with the Lord. I go to Mass every morning, joined a prayer group and spend time alone in prayer every day.
If you're Catholic stay close to the Sacraments. If you're Evangelical, try to find a Church where they understand the problem. If you can't find one, perhaps join us in the Catholic Church.