It's not the role of your psychologist to 'believe' you - they're there to assess symptoms and provide the appropriate treatment. If they're not capable of that, for whatever reason, you need to find someone better qualified. In the meantime research as much as you can about your condition as well as what advocacy options are open to you. Seek out real life support groups to supplement any online help you may be receiving.

BPD has different symptoms, severity, and cycles for each person - some people are mostly high functioning and have difficulty letting their guard down to receive the help they do need. But that doesn't make them less worthy of treatment. The bottom line is that BPD needs highly skilled professionals - and lets face it, there's not often an abundance of them. So you need to keep going, keep looking and don't give up - this is a highly treatable condition if the right sort of help is given.

All the best.