You sound great. Detached and clearheaded. Well done!
I think you did really well with his revealing of his job offer. And him not even telling OW, yeah that’s just not going to end well at all. Good thing you are out of that mess.
I like the fact you encouraged him with taking the job. It takes any concern or worry he might try to conjure right out of the picture - keeps this firmly upon him. You demonstrated you can look after yourself, showed a fearless side of you, and some really inner strength. I am proud of you.
As you continue, remember - you found this moment, this strength - it might slip and be regained a few times - it will become permanent.
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.