it takes patience, consistency, optimism, and understanding to show someone who has long endured bad behavior that you're capable of lasting change. Actions speak louder than words, and in the case of relationships, it's long-term consistent actions.
And in the end, maybe too much damage was done and you won't be able to reconcile. Is that all you're focused on? Ask yourself why marriage with this woman is so important to you now when it clearly didn't mean much not too long ago. Do you really want to be with her or are you just lonely?