Hello, I have struggled with porn addiction since I was young. Ever since then it was unlikely for me to go a week without the full PMO cycle.
In recent history I tried a nofap timer to count the days that I lasted and made it to about day 9, and crashed hard.
However, as of today I have gone ~15 days without climaxing. Yes, I know, don't watch porn, don't masturbate. I am a man of unsteady will so this has been a bit of a challenge for me.
I figured I would take it one step at a time, slowly un-building it as I go. My first step was to remove the climax. My understanding of this is that whenever you climax, it sends a shot of dopamine to your brain, so I figured that if I remove that final "hit" then it would ease back the other urges, and it has. For the past few weeks I was still on the PM part of the cycle, but wouldn't allow it to reach O. Due to this, the urge to watch porn and masturbate has been greatly reduced. Removing that final big hit of dopamine has made a huge difference. Without it, the slow flow of dopamine during the PM has been undercut.
Since I have reached the goal of cutting the O out of PMO, the other two are much more manageable and resistible.

At this point I feel like the hard part has passed and that I'm more in control now, and that's not to mention the benefits of semen retention for 15+ days.
Maybe this can help someone else, cut out the climax (the end goal of masturbation) and it becomes a meaningless endeavor. No reward = no justification for effort.