I’ve noticed that if I say “I won’t do this anymore at all”, it doesn’t work. But if I say “I’ll only spend this much this month on sex workers, gambling, etc.” I’m able to mellow down. I’ve also noticed some people suggest that moderation doesn’t work and you should try to be as cold turkey as possible.
If a person can moderate, I would call it a bad habit and not an addiction. To me, the inability to moderate is what makes it an addiction in the first place.