At the moment we are now focusing on me feeling safer and learning to trust again and we are doing that by him showing me some massive changes in his behaviour and making me his #1 priority.
Is he in counseling or doing any kind of self-help to discover what's inside him that allowed him to say 'yes' to adultery?
It's great that he's working on his behavior, but what I found in my own situation is that my fWH prioritizing me and doing all the open-book, transparency things he could do to make me feel safe was not enough. I needed to know why he did it. I needed reassurance that he was remediating the poor character which allowed him to toss his integrity aside and be the kind of person who cheats and lies.
There are a lot of therapists and a lot of books which still blame "unmet needs" within a relationship for cheaters choosing to cheat. If you read my profile page, which you can find by clicking the little person icon in upper right of this post, you'll see that this last time wasn't our first rodeo and I've got some pretty strong feeling about the "unmet needs" fallacy. I had caught him cheating before, so I found out quite painfully what happens when we don't get to the bottom of the character issues. 
It does take a long time to rebuild new trust after an infidelity, but currently, I don't believe that we ever move on from the betrayal unless we've been able to assure ourselves that our WS has grown from the experience, that he's become self-aware and that his integrity has taken on new meaning for him. It's not enough that they do it for us, or to maintain the marriage. It needs to be more personal than that, something they would have done for themselves because they just couldn't live with being the kind of person who gives themselves permission to cheat anymore.
You've come to a good place here at SI with lots of folks who have BTDT. We can be tough on WS's and expect a lot from them, but in the long run, I think it's good to challenge the current therapy climate with expectations for real change.
