I was both devastated and relieved when I was diagnosed. Firstly, it made me feel broken, like I hadn't grown up inside, or missed a step, or that I existed on top of a cracked pyramid, that a building block was missing... and I wasn't really a person.
On the other hand... I researched a LOT, talked to BPD sufferers and eventually came to accept my diagnosis. It took a weight away. I thought I just wasn't a person. That I had been born as a half-being and I didn't deserve to experience life, 'normally' Understanding BPD brought everything in my life into a new perspective.
There's a lot of neglect and abuse in my past and taking the BPD label meant I was stepping up to the plate to acknowledge, accept... and fight through it.
Do I ever believe I'll fully recover? No. But there's always hope of feeling better generally. Day at a time.
If you're in such doubt... really research BPD and own up honestly to your behaviour. Never lie to yourself about what you do and how you do it.
If you're still doubt it beyond all that... then demand a second opinion. I may be a 'difficult patient' too. But I've learned, and am still learning, asking politely and sweetly the first time gets you nothing. People take strength seriously. Blowing in there and making it firmly clear you want and are entitled to challenge a mental health diagnosis tends to get you the results you need.