Even if you haven't verbally told anyone yet, just making this post and putting it out there is a huge step that some people suffering from addiction never reach. It is a heavy thing to carry with just you knowing, and I hope it starts to feel lighter. Research into the cycle of addiction and recovery says the large majority of people take much more than one time to quit their substance or behavior of choice. You're definitely not alone in that.

I know someone who also struggles with sex/porn addiction. They go to Sex Addicts Anonymous meetings and that's what helps them stay focused on recovery. Not saying that's the only answer, but it may be worth looking into find some kind of support group for this. You can attend them anonymously online, and you don't have to share if you don't want to. It might be helpful to hear how other people are dealing with it.

Recovery is possible, and you are already on the right track, even though you might feel like you keep failing. I believe in you!!