I don’t see how he doesn’t follow the manual. Just by what you post on here you likely exhibit 5-6 traits of BPD. And we don’t know you in real life yet everything you post about every situation that occurs is very common for BPD.

I don’t think your pdoc wants you have this particular diagnosis. Why would he? He maybe wants you to finally have a diagnosis that fits your symptoms so you can maybe start working on those symptoms, with professional help.

You’ve been seeing therapists for years but your symptoms don’t improve because they either don’t address your traits or you quit therapy or therapy becomes about your idolizing and disliking of your therapists, so you don’t get better. He wants you to get better.

Unless your sister is also a trained mental health professional, her opinion can’t hold more value than your doctor’s.

Now you don’t have to discuss BPD with him or anyone actually. You can just work on symptoms with him. Ask him what he thinks needs to happen for you to handle life challenges better. You don’t have to call it BPD. You can talk about strategies of improving your reactions to things and your overall quality of life.