Hello how are you today. I struggle wit the same addiction. but I have been able to control myself bits more and more.
this is my advise:
PRAY TO GOD. in the morning, noon, evening, before u sleep, dont make a schedule i mean but instead just pray alot about it when you feel you need to make a need to do so as well.
You cannot overcome this addiction by yourself or with the help of a human, or a therapist, only the Lord can guide you and save you. Do not make anything an escape or alternate means, as in say replace this with another addiction dont do that instead i simply say pray, get on your knees and become humble for Christ.
CONVINCE yourself you dont need that trash in your life.
but dont HOUND yourself if you do it, that may lead to stress which may cause you to do it again in the future.
Instead become at ease, relax your mind and serve the Lord your God by praying and staying clear of anyone who does that addiction or anything that promotes it say certain comedy movies that do.
the definition of masturbation part of it is MANIPULATION of the genitals.
that is not God's plan for your body he wants you to only do sexual stuff with you spouse someday, no other, clear your mind and keep yourself from any sick thoughts.
DO NOT IDLE: on the computer do not browse aimlessly, but focus and go to your goal, check your email then GET OFF go outside dont screw round looking for music song or something then you will end up stumbling it can happen so only use your computer for the PRECISE things you NEED to use it for at the time.
LASTLY: COMMUNICATE: stay in contact with other christians - this will help you and strengthen you but as i said earlier do not linger on humans as your savior, however if you seem to not be able to control yourself find a christian friend and read your BIBLE with that person - best a male friend if you struggle with lusting for opposite sex.
then when you control yourself, you will be so happy you will have accomplished your mission and God will be smiling cause of your resilience to sin. =))
Have a good day God Bless You.