Hello WaYforward,

Is she actually diagnosed with BPD? Any other illnesses?
It sounds like your H is stuck in his role, and that is understandably frustrating to say the least. It must be even harder that you are part of this dynamic, watching.
How, exactly, is he caretaking physically? Emotionally is a given... .
There are lessons at the top of the board which may help you to start (apart from their dynamic, but maybe you can pass on some things to your H). Take a look.