Quote:
He must've been very unhappy with me to walk out on his kids and find ow a better option.


No - he must have been very UNHAPPY. Period. End of sentence. Not due to you but to depression. And a rational person who feels his marriage is failing goes to counseling and works on it with his spouse and works on becoming a better spouse himself.
(I have a childhood friend whose wife of 25+ years has terrible OCD, treats him badly, is quite difficult. he's gone to counseling with her, but she's not receptive. He's a pilot and could easily have affairs. He's committed to the marriage though and keeps working on his side of it. )

Your H, like mine and others, took the easy way out - have an affair, feel temporarily better from the brain chemicals of infatuation, THEN decides he must not be "in love" with you, and blames you.

It's not your fault he got depressed and it's not a comment on your worth that he had an affair. (BTW, EVERY guy that I have dated since my divorce has thought my ex was NUTS for leaving me! )

Interestingly enough, you almost never see a spouse here leave for someone objectively "Better". Some leave for money. Some leave for younger if they're panicked about their own aging. Most seem to "affair down" with someone who is "lesser than" and sees them as the "big man" instead of an equal. Often the OP turns out to be a whackadoodle or an addict.I can hardly remember a case where a guy left for a Christie-Brinkley-rocket-scientist.

And just for the records, I met a number of DBers in person in the past and they were an absolutely normal, attractive, interesting group of people. Not a lame reject in the bunch. So believe me when I say, while we all can and should improve, THIS WAS NOT ABOUT YOU. And if you H says it was, it's because he has to find some way to justify his actions to himself.