Betrayal trauma

It's getting close to 12 months since he last viewed porn, there has also been more to it than just the porn, he has also had other contacts kept secret including his ex mother in law not married but to the ex before me. As well as other females he knew before me and that are mutual friends with his ex. The porn lasted for the first 2 years of our relationship, the other contacts for the first 3 years . I also found two attemts to look up porn in that time but the blockers stopped him, so in my eyes its still there. Around Christmas he had a revelation and said he really did love me and all was going to stop and he was a changed person since then things have been slowly getting better, he hasn't skipped up but I can't stop living the past over and over again it still keeps coming up in arguments I am so damaged by all of this. When we first met we both agreed that we didn't want to get married again but my views have now changed and I now think it would show a deeper commitment (given the fact in our first year together he was still trying to give off a single image) I am now looking for that deeper commitment from him to show the world and me how commited he is. He's still stedfast on never marring again so I've just said ok I can see there's some big decisions I need to make and just left it at that. Also given just last week he said I meant more to him than any of his ex's ever did. So I said I wanted more given what's happened but he won't give me more( he was married twice before and the last one a long term relationship 10 years ) I don't want to lose this relationship but want to stand my ground and want every one to see he's commited to me given the fact he was trying to look single and was also in contact with his ex wife from over 10 year's ago when we first got together .