TM, do understand that people who have been together for 30 years before BD have moments of wondering if they really knew their spouse.
Yes, there are plenty of people who put on a good act and can do so for extended periods of time. Remember, this is someone you lived with and had daily contact and interaction with.
There are other people who make drastic changes in themselves and so we THINK they weren't the person we knew. When the reality is, at least prior to the changes, they WERE that person we knew.
I too struggled and still get down about my kids not having parents who are M and living together in a healthy M. In all fairness, that will never be the case for D14 as I am not her bio dad. All I can do is take heart that I will be the best dad I can be for them, regardless of the future. It's not an easy thought to make stick. Still, it's all we really ever have.