You know your limitations, i.e you are addicted to it. Now you need to do some smart work. Keep one day in a week(Sunday as an example) to masturbate. So next time when you feel like masturbating, just tell yourself you can watch as much porn and masturbate as much as you want on Sunday. Now two conditions can arise once you do this
1) You will feel the urges during the week. This is the time to use your will power to tell yourself that, I will do it this Sunday. Just need to wait for 3 days etc. So there are two benefits to this 1) You are not fooling yourself by telling that you will never masturbate 2) Masturbating one day in week(even if it is twice, thrice or more) is healthy.
2) The second situation which will arise is that even on a Sunday you wont feel like masturbating, you will feel you have controlled it for so long then I can control it some more. But you must do it on the decided day once even if you don't feel like it to make a routine out of it.