I have read this thread again this afternoon and I am seriously wondering if I have missed something or if there are other threads you have done in the past?
As actually in a way I feel sorry for you both and think you maybe need some counselling too, I am also a little shocked at the reactions.
From an outsider reading this thread I see some important points which I think explain a lot and maybe you can see them clearer, bits I have got from posts and put together........thread thus far...
1)He has masturbated to some porn, you found it on the internet history and went ballistic.
2)Your reaction and own insecurities made the whole situation of a natural masturbation incident become a huge overblown affair. You then proceed to check on every part of his life, work, phone, bank, bills, work over a bit of porn history.
3)He then decides because of the OTT reaction it's better to hide it. So he goes for the text/chat lines hoping you don't notice to try and keep you happy and "prove" he has got no outside stimulus. He has not had an affair.
4)You know this is happening as you go looking for it by snooping which has driven him to secrecy. But even then he is not rubbing your nose it it, you find something about once a year?
I really hate to say it, but I think you seriously need to look at your own attitude to sex/masturbation as the whole incident here seems to have been caused by your own admission, your reaction to finding out he had used porn.
Men and women wank, that's life and that is nature, it's healthy not something that should be dirty or demonised in anyway. He has been made to feel ashamed for having a wank, which is not right.
Men tend to operate in the here and now they don't have an imagination so there brains are hardwired for images. There is a reason that porn is the biggest thing on the net. Porn/lads mags etc are as old as the year dot. Like I say you won't find a man who has not been exposed to porn in his life if he is honest, it is actually a natural thing to do.
A lot of women don't like porn as they have confidence issues which is clear you do from your posts and they think why not me, am I not enough.
It's equally normal to masturbate even if you are having a healthy sex life, it's not a reflection on you. Again if it's an addiction, violent or overly secretive then it's an issue.
I have found most people I know with sex issues tend to also have problems with sex themselves, "dirtying" normal things and not wanting to have sex etc.
I think here you need help to look at your own self asteem and also your own issues surrounding sex.
I hate to say it if you do leave him, when you meet someone else, I'd guarantee my savings, he would have been exposed to porn, had a wank and probably will do in the future, be it once a week or once a year, you just may never know about it.
I think you do need some counselling as if you go through life like this you are going to be so unhappy.
It does seem here, he got caught via the history that he had watched some porn, you went ballistic and started snooping on every aspect of his life which made him become more secretive about his masturbation habits and looked to other solutions hence the phone/text lines.
All this and made to go to a sex addict clinic and made to feel dirty for watching a bit of porn, like I say unless I have missed something, I actually feel sorry for him, it's something all men have done at some point that is a fact. You'll never be happy if you want a man to never, ever cross porn it's everywhere and it is natural.
I think I'll leave it there, but it's sad to see you tearing yourself to pieces over something all men have done as reading through this has all started due to your reaction over a bit of porn.