I understand where you're coming from in a number of ways. Firstly, the more you pray about it the harder it gets. I think this is the pink elephant effect. If I tell you not to imagine a pink elephant, you will go right ahead and imagine it. The more we try to avoid pmo the more it's on our mind and the more tempted we are. Rather than think "I musnt't be tempted, I musn't watch porn" it might be better to think "I'm going to try and make today busy with this hobby or that passtime and try and make myself holy today for God" so you are trying to do something postivie rather than keep away from something negative. Also, I know how you feel about some Christians. I go to a foreign church here and there are often a lot of regular churchgoers there and also some who are not originally that religious and maybe going more to meet other people from their own country. But I sometimes found I had more problems there with the stronger Christians. Sometimes I felt in life that some of the stronger Christians could be more judgmental and sometimes as if they thought they were morally better than others and looked down on people who weren't. This is not how it should be though. We are all sinners and nobody is better than anyone else. I think we should all humble ourselves and treat each other with respect and love.
Anyway back to pmo thing, it is a struggle because we have conditioned ourselves to do that. Sometimes, we have taught ourselves to do that to relieve stress or when we feel horny. So every time we see something hot or get stress, it's as if our brain associates that with orgasm and dopamine rush and asks us to do it. So we need to get into the new habit of not doing that. It is tough to reprogramme our minds and bodies. It's gonna be painful and some days you will feel like you're gonna explode if you repress the desire to pmo. But it gets easier and you get stronger and you get more self control as a result and that feels good when you can finally say "I could do that but I'm not gonna" and just walk away.
One other important thing is to reprogramme your mind as to how you view porn and masturbation. To see porn as filth and disgusting. To be able to look at people in porn and in life not as sexual objects but who they are, beautiful objects of art and someone's daughter or son, brother or sister. This site was useful for me in helping me with that :-http://mychainsaregone.org/articles/pornography-addiction/#sthash.Fiz95VYg.dpuf
Also someone told me that masturbation is having sex. I mean there are different kinds of sex, right? and masturbation also requires a kind of penetration of hand, and orgasm and ejaculation as well as often lust involved with the fantasy. It is an act of sex and usually acting upon lust, not love, with the things we imagine or look at. This is where we are going wrong. Sex is supposed to be an act of love with loving husband and wife and we are misusing that.
Once you change the way you see pornography and masturbation in your mind it can help you a lot. I pray things will get easier and you will find yourself free from the chains that bind you. Bless you.