There is a difference between self esteem and sense of self. It's subtle but- low self esteem is a constant feeling of worthlessness. Sense of self is about boundaries- knowing what is "you" and what isn't "you". It's also based on several aspects of you that don't change, even if circumstances change.
Job loss can be devastating but even if it did happen- a person doesn't disappear. Someone might be an accountant- and they still are one, they still have the skills. For someone with BPD, this sense of self is shaky, a criticism, job loss, feelings of shame- might feel like self destruction.
My BPD mother had aspect of NPD. She had a strong sense of entitlement and superiority. Yet, she also needed constant proof of this to validate that, by having people act in service to her, by spending money. Underneath it all, without this external proof, her sense of self was unstable because she relied on this external proof of it. One would see her as having high self esteem and entitlement, but that outward appearance didn't match her emotional self.
PwBPD perceive themselves as from victim perspective. In victim perspective, they are not accountable. The "benefit" to them is not that they do this on purpose- it protects them from feeling shame which is intollerable to them. When your wife complains about someone at work, she perceives this from victim perspective. When you try to help her "fix" this, it feels to her like contradicting this position, and feels like an attack. Your intentions to help are not received like this and the two of you end up in that circular argument.
Understandable that you want this situation to change for the better but you've seen that approaching this logically with your wife doesn't work because these are her feelings and feelings are not logical. To someone with BPD, feelings feel like fact.
Maybe some things she says are outlandish but being dismissive will feel hurtful to her. You also don't have to go along with what you think is lunacy but in the moment, it's not lunacy to her. The benefit to you to see what isn't valid is that you won't react emotionally to it as much. If something isn't true about you, you won't feel as much a need to defend it (JADE). Reacting just adds to the drama.
How this goes is unpredictable. Whether things get better or not, isn't possible to know. A first step is to step away from the drama dynamics, learn about BPD, learn relationship tools like how to validate and not to add fuel to the drama. It seems like your therapist has an idea about the situation. This is the person with whom you can share personal details and so they can guide you on how to proceed with specifics, while you learn about BPD dynamics.



