WAW 20 years and wants out

[gutwrenching]

She said the OM was not the reason we are getting a divorce

Two things I take from this.
1) She is right and you should validate that. You did in a way but maybe could have done better. The A is not the root cause, the root cause is all the issues that led to this and as you know, you each have to work on those things

2) This is also typical WAS justifcation for what they are doing. Blaming the LBS for pushing them to the A. Unless the fog breaks, they will always say this and not actually realize they are partially correct

Now, try to maintain control of the emotions. I sense raging emotions in your posts. I might be wrong. But the calmer and more matter of fact you are, the better.