That's a good question. I'm currently on day 30, and I did a little peeking yesterday (also lasted about 5 min). In my case it was before bed, I couldn't sleep because I had taken some mushrooms on the afternoon and the effect was still fading. So I decided to smoke a joint to relax and boom, I got horny. The moment I've come to, I turned off my computer and went to bed, started to chat with a girl I know from college and listened to some podcast to fall asleep. It worked. I believe that if we were able to realize what we were doing and stop it, that's a very good sign. The more aware we are, the more easier it gets to create willpower to stop those habits. Think about the progress you made so far, and if you don't stop peeking the urges will return, stronger and stronger. Don't fool yourself, be the master of your own mind, control yourself!
The moment you peek is the moment you peak. First off, lusting over fetish material 3-5 minutes is more akin to drooling than a peek. A peek is less than a couple seconds. From the looks of it, you already gave up on this round, and that's almost always what happens when someone drools. If you're honest with yourself, you probably already decided you were going to give in to lust some time before you clicked onto those tabs. Then, drooling over that material for a few minutes was just a pretext for what you'd already given in to doing. But, the more you looked over them, the stronger the lust grew, and the more your will weakened. Make this your true attempt, by setting the exact date you must last until. Next, to answer your question, you must build muscle memory, that's how you avoid peeking. That means, you'll train your mind to look away, click away, ex-off, and delete any image or thought that causes you to lust. That takes time and effort, but you'll soon learn to quickly kick down all those lustful thoughts and instantly turn away your eyes from anything that causes you to lust.
@Cody Kindred it depends on the reason you have started No PMO and the motivation you have to abstain. You're very young (21) literally all the life in front of you, which is a good thing, the bad thing you've got somehow problems with your penis at your young ages. I hope for you is not something very serious or bad, but it's a good step already having abstained for more than 2 weeks: I'm 38 and just now I managed to abstain for more than 2 days,( 2 day and continuing now) basically because I never knew I had to abstain to try to solve something: actually i was masturbating more with the idea of bringing blood to the penis to feel it fuller. Well, how to avoid peeking? once and I hope it wont happen to you, but once you touch the bottom and see your life going to be destroyed, you will stop peaking ( extrema ratio ). Anyway I see you already have more willpower than many other older guyz here, so you're on the right way. One day you will decide...enough is enough if you see your problems persist. Those fetish pages that you're tempted to watch should prove to you that you're still far from healing: think like healing when you feel lust for having sex, having an hard on and feeling that you could fap even watching just a photo of a sexy girl: nothing extreme, no raw sex, no orgies, no fetish, no foot fetish, no transgender: those things kick the dopamine much easier if you were depening on them to feel pleasure. Healing mean for me that you're so hungry that you could fap with a rock hard dick watching lingerie catalogue as those we had at home decades ago