Is this the end of my marriage?

[Arwen_in_NJ]

not sure what to say if she brings R or OM stuff up - do I just tell her I don't want to discuss R issues or do I let her talk?

If she brings up R talk, let her talk! The most important thing you can do is listen. Don't get defensive, don't try to justify your feelings or behavior. Just acknowledge and validate what she says, even if you don't agree with her. One of the best phrases you can use when DBing is: "I understand how you can feel that way (or why you would have felt that way)". After all, her feelings are her feelings and they are valid, even if her perception of a situation is different than yours.