Relapsed after 120 days

So one day this year, I drew the line with my porn addiction and started the 90 day challenge. I, to my own surprise, found a great deal of success with this, and made it through the 90 days without too much trouble. Because I also have a porn induced-ED, I decided to keep going for as long as I could. Some time after the 90 days, I began masturbating again, which seemed to have enabled the chaser effect. While I started off masturbating to nothing but my imagination, as a couple weeks went by, this started not being enough. A couple triggers from movies I had to watch in class as I am a film student, combined with some nights of terrible melancholic sadness, led me to relapse and watch porn again for the first time in nearly 4 months. This was a few weeks ago. Since then, I've watched porn 3 other times, all during intervals that were each a week apart. While it shows some will power that I'm able to limit my use of porn to once a week, I really don't want to be using it at all, despite successfully completing my 90 day challenge on the first attempt. I feel like every time I do, I'm cheating my mind, and my porn-induced ED will never truly reverse if I continue to watch porn on any basis. The problem is, I simply don't feel the same control or discipline over myself when urges come at this point, compared to that during my 90 day reboot. What are things I can do the stop what feels like a train leaving the station of my progress and regain control of myself once again?