Those flashing thoughts are normal, expected and not something you should be ashamed of. They happen because your ego has to take its chances. As with every recurring undesired thoughtform, you must find something to redirect the thought every time it happens to you, “rationalize” it in your mind instead of resisting it. For example, think “it is normal that I have this thought after all the memories I’ve piled up on this, here’s 5 reasons why I think watching porn no longer serves me”. By the time you’ve enumerated those 5 things in your head, your urge is gone. As you do this, the thoughts will appear less and less often until, one day, you’re free.
I beat a porn addiction I picked up when I was 9 myself. Believe me, it gets better if you give yourself this understanding. Just don’t judge yourself, accept that the thoughts you have are expectable given your experience. Anything but responding with a negative feeling (rejection, frustration, etc), because a negative feeling will create “trauma” about it instead of letting these ideas go.
This last bit is the key to healing anything. If you manage to transform any feeling into acceptance and understanding, healing is a matter of time.
“Fuck I did it again” turns into “it is only logical I still have these, I spent 20 years watching this”
“Agh why won’t this stop” turns into “I know this will stop once I’ve pushed it aside enough times”
“I can’t control this” turns into “it’s been 3 days since the last one, I’ll make it 4 now!”
And so on… Stay strong, mate!
You’re basically engaging your brain’s neuroplasticity to rewrite the neuronal paths you’ve written for so long. Those paths used to be horny>masturbate, now you’re making them be horny>(new thought). Every time you use the new path, the old one becomes slightly weaker, and eventually the new one is stronger. So you could also see these random thoughts as an opportunity to do a little bit more damage to the old path!
(Edit: I admit I did not read the whole thread before posting advice, so I didn’t see OP recovered. Hope this is useful to someone in the future in any case!)