Another book you should get is “No More Mr. Nice Guy”. Sounds like you have what as known as Nice Guy Syndrome.
Doesn’t sound like an affair. Is she secretive with her phone?
She is secretive with her phone. I saw one time she was texting a 2x divorced childless female friend, something about "make sure you document what he said about your work". Part of the evidence that I know the BD is coming. I guess it could be an EA but I doubt it. I'm not sure it matters to me honestly -- either way she's being secretive and hiding things from me, it's impacting my trust of her too.
I do have that book. I bought it last year when I was lurking on Reddit's DeadBedrooms forum. Started re-reading it yesterday as a matter of fact I definitely suffer from NGS in many ways.