I've name changed for this thread. I have a BPD diagnosis (got diagnosed in 2003). I had classic symptoms throughout my teens and early twenties. I self harmed for years, took a number of overdoses and attempted suicide. I was hospitalised twice.
I then managed to hold things together for thirteen years. Sorted out my life, got my degree, worked in the City as a lawyer.
Having thought it was all behind me I ended up relapsing spectacularly at the end of last year and am still trying to get back to normal.
All I can say, from my experience, is that I don't tell people about the BPD. I haven't told family and very few friends are aware. I also have major depressive episodes, which seems far more socially acceptable than a personality disorder. The contempt at which I've been treated with, back when I was in my early twenties, from various healthcare professionals, was ghastly. Personality disorders seem to bring out the worse judgment from a significant number of people.
I haven't engaged with NHS mental health services this time around - I'm fortunate to have been able to go private and access DBT with a private clinical psychologist. I don't want to be judged or labelled or face the kind of horror I had to last time around and I fear that NHS services won't have changed in the intervening period.
All I can say, from my own experience, is be very, very careful as to what kind of label and diagnosis you want. Having that on your medical records is not something to be taken lightly. There is still a massive stigma. It doesn't help that personality disorders are very difficult to treat as well, which means a lot of the time, you'll be written off by local mental health services, who don't want to take the time or effort to try and deal with you.
I'm sorry to be so overwhelmingly negative. Others may have different experiences. Good luck, in any event, OP.