Because of the vagueness of the question (and I understand why you wouldn’t want to just throw your business out there) the answers will have to be somewhat vague too but I’ll try. Really I have no business offering advice, so keep that in mind.

Let’s say it’s like your example, beating a wall until you hurt yourself. You’ll need to seek professional help. It’s not that therapy itself will “fix” you, but a professional could give you tools that you can use to help yourself. You can’t remove walls, you can’t avoid them, it’s not really something you could stop yourself from doing easily, and so I would think you’d need assistance.

If you have to avoid therapy and it’s something else, maybe a porn genre that you’re not proud of, I think you can try some stuff to help. For one, if it’s digital and you have it saved, delete it (files, bookmarks, whatever). Do what you can to raise the barrier of entry to partaking in this hobby or fetish. Similar in my mind to someone fighting an addiction with drugs^* or even just shitty food, if it’s not in front of you you’re less likely to think about it. Really, this is something you don’t want to do, but you can’t seem to stop yourself, so it is a sort of addiction. So, do some study about how people curb addictions and try that stuff. Same if it involves a physical object, if you can, throw it out. Even if it cost a lot of money, the point is you don’t want to do it, so get rid of it.

Replace it with something healthy. Going back to if it’s porn, since i don’t know, replace it with a “normal” genre. Every time you get the urge to partake, do the other thing instead. This is like that advice when you crave something sweet, to eat fruit instead of candy, so it might be hit or miss. But, the point is to get that “release” through better means.

I also keep hearing this idea that your brain can’t “tell” when you lie to yourself, and so the way you talk and think about yourself has a huge impact on how you behave. I’ve never done the deep dive to figure out how much solid evidence is backing this but it’s worth a try. Do the mantra in the mirror in the morning type of shit. Even if it feels stupid, who cares, you’re allowed to do stupid things. Tell yourself that’s not who you are, this is not what you do, and give it time. Do your best to stop shaming yourself when you fail, because you probably will for a little while yet and that’s just part of the process. Lie to yourself long enough, and maybe it will stop being a lie.

If what you’re doing involves another person, get them involved in your improvement (if you can trust them). That accountability helps a lot of people. If what you’re doing affects another person negatively, we’re back to the seek professional help, as soon as possible.

Good luck!

^* I know drugs have more to it than that^

Depends on how unhealthy really. If you’re beating yourself up for jerking off once a month/every two weeks to legal porn, chill thats fine. If you’re getting so high/hammered you do bad shit bi monthly/monthly, you need to adress that with professional help immediately. If you’re not dealing with a mental health issue that leads you to dangerous behavior monthly/bi monthly, that needs to be adressed professionally. If your fetish contains illegal material, you need to stop looking at it as a fetish and RIGHT NOW seek professional guidance. I am pretty tight with social workers in a several states and a couple countries. You can message me if you want help finding resources for your particular case. Without the context it’s pretty much impossible to answer though.

Therapy, if they are really so bad they are affecting your life negatively. Usually there is something bigger behind whatever you are struggling with.

Poorly.