Not sure if I am correct in my assumption here but he might not want to change your diagnosis cos of insurance reasons. That seems to be why so many people are misdiagnosed as BP, just so the docs can get the money out of the insurance companies.

Look into it by yourself. If you think you have BPD then find treatments you can do in your own time or with the help of your T. Your treatment plan should not be entirely up to your pdoc. DBT is brilliant for BPD and is starting to be more widely used and recognised as a treatment - even more effective than meds for many people! I am sure you can find some resources online to help you in your own time.

Goodluck