If you realize that you are going in circles as you described earlier, that cycle of act out- get my stuff together- rationalize that you're passed it- and then act out again- you have two choices,
Either you decide to commit to working a system to get off, or you stay on the merry go round. You put it really well in that post earlier summing up the cyclical nature very succinctly. The truth is though, that even when we 'convince ourselves' that we are past it, even at that stage- usually just below the surface we are brimming with self hate and loathing knowing that we are lying to ourselves.
At least that is how it works for me. Yes, I try to imagine myself as that 'clean cut guy' in beis medrash. His shirt is always pressed, tztitzis neatly together hanging at his sides at 180 degree angles. You know that guy? When he checks his email- that's all he does. Check his email. He'll maybe message his father about doing great in seder, or learning or whatever, and tell his wife his chavrusa is coming over after seder. Then he merrily goes back to his avodas HAshem. He sees those signs about internet asifas and dutifully goes as a good yid, to hear about how important it is to stay away from these dangers. At that time, he feels guilty for checking Yeshivaworld and voz iz news more than twice a day. With a sigh he resolves that THIS Elul he is REALLY gonna make that change and ONLY look at the kosher news once a day during bein hasedarim. He's got the device fitlered and shmilterd to the hilt- because that is what the rabbonim say to do. But really, he does not feel that drawn after porn. He may be tempted, in much the same way as when you smell good food from a treif restaurant. It smells good! But he knows- It's not for me. I'm a ben Torah.
Yeah... lolololol. That act can last anywhere from an hour to a day, to a week or two... I'll pass by the mirror a few times and actually believe I am looking at that tahara yid.... and somehow then I usually find myself quietly locking my bedroom door, tearing my tzitzit off in the privacy of my home and voraciously devouring hours on porn and chatting.... At that time- Don't even talk to me about that clean cut guy. I'm not in the mood. I'm BUSY!
Then once I'm done, I pay the piper again- I feel my guilt, I shed my little tears and I'm ready to put my tzitzit back on at their respetvie 180 degree angles...