Confess Right Away
I was an addict for thirty years and I was saved through a neder, like a nazir.
I believe that a lust addict can be modeled effectively almost as a person with multiple personalities. Usually he believes he is a tzadik, and he feels bad about his "bad habit." When he is staring at an erva and sinning, he continuously chooses to keep doing it. That is a rasha, not a tzadik. He is a rasha who wishes he were a tzadik.
The brain has separate pathways that support those two personalities. You need to keep your thoughts off the bad pathways long enough to build new ones to replace the ones that you don't want. For example, I used to sin when I was stressed out at work. You cannot choose your way out of that behavior. You need help.
Help for me came in the form of a neder. I realized that the entry point into my rasha brain was the initial lewd thought, the second look at a woman, etc. While I had on my tzadik personality, I made a neder that I would do teshuva for the thought by confessing out loud, and I would do it ASAP (usually for teshuva there is time, but not for sex addicts.) Over several years, this starved the rasha's brain and gave a chance to the tzadik to build acceptable reactions and behaviors. Today I do not have the same impulses I used to have.
If you go this way, I would suggest making it a short neder first to try it out, and if it works for you, then when it expires you can make a new one. You may notice an increase in inappropriate thoughts at first, but the neder will also give you the ability to fulfill it. (Don't forget to allow for times that you are not allowed to speak, such as davening and any other time the halacha requires you to be quiet).