You should be open to the possibility that your habits are normal.

I don't know specifics. I don't really want to know specifics. But as long as you're not doing it in inappropriate settings, harming yourself, or harming your sex life with a partner/making it so you prefer masturbation to sex then you should be open to the possibility that you're a young man, and young men masturbate a lot.

Similarly you need to be open to the possibility that your ideas about masturbation are being influenced by people with ulterior motives. There are ties between far-right movements, manosphere content, and masturbation abstinence. Before you come to the conclusion that you are actually experiencing a problem, I think it's really important that you have considered these angles and how those are influencing your goals.

If all that has been considered and you're about to start masturbating on the train or something:

Start with small benchmarks, and be clinical about it. Don't beat yourself up if you don't make it, just adjust the goal. Start with a day if you have to, "On Tuesday I won't masturbate" - done. If you fail try again in a couple of days (while being kind to yourself about it, or at least neutral). As you do that you can expand that time to more of what you're hoping for as a healthy baseline (again, keep in mind that masturbation abstinence communities are not a good source for this). Slowly expand from one day of abstinence a month to once a week, etc. Don't tie it to gimmicks like NNN or go straight for a week or something, that's never a sustainable way to keep something under control. It just makes you crave it and can lead to binges when the time is up.

The goal is to prove to yourself you can control it. If you are actually addicted then this is closer to an addiction like food than something like heroin. It needs a healthy, reasonably sized spot in your life. Not for you to try and quit entirely.