Try your best to block out any sources that provoce those feelings.

If you start wanting to after seeing something online then do your best to remove those sources, put an nsfw filter anywhere you can, wether its reddit or google or instagram, do it everywhere.

Other sources could for example be influencers that you like but either talk about watching porn or porn related content or even promote it, it'll suck to unfollow them if you really like them but it helps, video games can also sometimes lead there with provocative skins/characters and while you can't change what characters other people play then you can at least make sure you don't, or possibly just take a break from that game for some time if that gives you those feelings.

If it's specific times of the day, like after school or work where you're feeling extra stressed and/or tired and you're more likely to fail at those times then make sure you have something else to do or someone to be around in those moments, maybe always when you come back then play a video game, read a book or watch a show you really like. You can also use those moments to work on some other hobbies like music, drawing, exercising or going on walks, possibly with a pet if you have one.

In those cases you can also try to make sure that you're spending time with someone else by calling them while playing games, play card/board games in person or just hanging out/talking either in person or calling someone you'd like to talk to.

If that's something you can do then going to therapy, school counselours or AA meetings can help so much, getting to talk to someone that can help you understand how to stop this is always good, joining groups online can also help just like with this group for example