i notice this pattern a lot. When someone is close to 90 they fall. Hashem wants them not to get complacent and hit 90 easily and say "Yay, I did it, I'm healed". He wants you to realize that an addict will always be an addict, and even after 90 days - although it might get easier - we have to keep up our guard. He wants you to take your recovery to a NEW level and not be satisfied to just hit 90 and be happy. That's why he often makes the person slip right before 90. I have seen this many times, and I have been in touch with Him about it... (just kidding, this is just an hypothesis
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But the good news is, that you can keep two separate counts of 90. One where you didn't mz"l, which will be coming very soon, and the second of not going to innapropriate sites, which you can start again TODAY.
Keep up the good work. Hashem is very proud of you. Think of how far you've come since the past!