Rose said exactly what I wanted to say: the affair is on her. But you, Last79, need to own up to whatever your shortcomings were as a spouse. I'm not saying it was all you there. Just sounds like you two had an unhealthy partnership for a long time.
- You stopped nurturing your relationship. - Your W wanted to connect (talk) with you better but you didn't respond adequately. - Your W had some ambition to get her own career but you didn't support it adequately/enthusiastically. - You believe financially supporting the family is all you need to do; but were you helpful at home? Did you let her get some big breaks away from her kid/household duties?
Your W having an affair is absolutely awful and nothing absolves her for that. But you can't control her. So I list the things above to encourage you to take a good hard look at yourself.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final