Keep in mind that the other woman isn't getting the complete story -- about you or about your marriage -- from your husband. She's getting a filtered version of his story, in which you are not painted in a particularly flattering light. And even if he doesn't say anything bad about you, believe me it's implied by omission. So what does the other woman care? She feels sorry for this great guy who she has been led to believe has a not-so-great wife.
I'll say it again: she owes you nothing; he owed you everything. Let him go.