... My mother was diagnosed when I was about 12 years old and she believes the illness runs in our family ... I wonder more whether or not I have BPD myself or if my outbursts are more an effect of learned behavior
Dialectical behaviour therapy (DBT) is considered cost effective therapy for anyone who struggles managing strong emotional dysregulation. E.g. if you weren't taught that as a child (or have BPD). I was lucky, my father taught us good skills.
BPD is often misdiagnosed as it has cross over symptoms with so many other issues such as neurodiversity and PTSD.
Self awareness is the main thing.Your post suggest you and your mother are very self aware, those that aren't tend to remain undiagnosed and bully others. This is why the health sector has moved to using "spectrums" like the DSM-5 scale (30% of the population) rather than labels.
The best approach I've seen is "treat the symptoms, not the label". Ironically, a lot of health workers are on the DSM-5 scale and undiagnosed, and "unconscious bias" comes to play. E.g. I've seen senior consultants make very prejudicial statements (not out of ignorance) which is a sign of a lack of self awareness or attempt to manipulate. So learn "Best practice" from those that clearly demonstrate it themselves, often other suffers can't, but they can give you moral support or good book references. Hope that helps x