My husband has absolute penile dysfunction, what could it possibly be?

[SAAngelface]

My husband is a very fit, healthy male of 50yrs old. From his looks and fitness very few believe it when we tell them he is 50. The sad part is he is totally and completely impotent since he was 42yrs old. Never used drugs (for gym or muscle building) of any kind, never had an injury on his penile region, no medicine use and no smoking. The biggest problem is that he admitted to being addicted to porn. He only gets an erection while watching porn. We had a rule in our marriage, that we were not to watch porn secretly but we coul occasionally watch it together. Our sex life was amazing then all of a sudden it just FLOPPED. I have tried every thing, suggested another woman to join us to see if that wouldn't help, but NOTHING RISED. Drs can't find the problem and theres nothing medically wrong. I blamed myself,my looks my everything afterwords. I'm really depressed because i have done some studying and it all boils down to the porn addiction and obviously maturation. We are technically divorced because of it but he asked for a last chance and believe me, if I didn't REALLY Love him, I would have left him and found myself someone else. This is not good for either of us. I broke all the spare phones and tablets on which he could be watching porn and he claims to have stopped. I havent caught him yet, in the past 6 weeks but its STILL a floppy situation. Any positive input would greatly be appreciated.