IS MASTURBATION CONSIDERED A SIN?
Jesus said, “I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart” (Matthew 5:28, NIV). Masturbation involves lust. It is adultery and is therefore sin.
For detailed help you might want to get Every Man’s Battle by Stephen Arterburn and Counterattack: Taking Back Ground Lost to Sin by Jay Carty. Both of these books are thorough, practical, and well written.