My significant other needs an accountability partner -- And it's not me

For years, my boyfriend has been struggling with a porn addiction. It disgusts me and I feel betrayed. It started off as videos, regular porn videos. And it turned into obscene, taboo, and frankly disturbing porn. Once he got fed up with his own actions, he turned towards more tame tumblr blogs... But they're nudists. He uses it as a way to get a fix. He has used NoFap years in the past, but a woman on a help forum seduced him, I guess, and he cheated on me and sexted with her for about a week, even after I found out about it. It was about this time that he went to tumblr.
A couple days ago, I found out he has been looking up a specific user on tumblr. Trying to get more personal information about her. Thankfully, her log had been deleted.
Him and I are Christians and would like to abstain from sex until marriage - we are both virgins.
I have tried being his accountability partner in the past, and as recent as a few weeks ago. But he is dishonest with me, and will be manipulative with me to save my feelings. I feel like I have tried everything to help him. I have been open, I have been angry, I have been more sexual (not sex, but sending pictures and such), and I have also tried to sit back and let it run it's course; see if he could get over it on his own.
It has been 4 years since we started dating when he was 19.
He's been addicted to porn since he was 13, and he is now 22.
I want to marry this man. He is a wonderful person, a devoted Christian, and a kind-hearted individual. He treats me right - except for the porn problem. I have asked for help on different sites and gotten the same answers:
"There is nothing wrong with porn,"
"Christians are oppressed by their fake god," and
"If you have sex, he will stop wanting porn."
I feel betrayed, unwanted, and ugly when he chooses porn over me. I feel like this not unreasonable.
Although I want so badly to be his accountability partner, I know I am not enough for him in this aspect.
I am asking for a MALE accountability partner for him. I will not accept females, simply because of the past. He has requested that they be Christian (not that there is ANYTHING wrong with anybody that isn't - He just wants spiritual guidance as well) and older than him by a few years maybe, for more wisdom. I am at my wits end, I have nowhere else to turn. I need somebody to help us. Please help me, help him.
**The interaction between him and his accountability partner will NOT take place on this forum, because I no longer trust him on forums. It will take place somewhere else - probably kik, I'm not sure yet** PLEASE reply if you are interested in an accountability partner.

 

Thank you for your support