Personality Disorders Support Group
Personality disorders form a class of mental disorders that are characterized by long-lasting rigid patterns of thought and behaviour. Personality disorders are seen by the American Psychiatric Association as an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the culture of the individual who exhibits it.

If I read this right, you stole drugs from your older family members? So the problem is, you were raised by addicts... you didn't really have a fighting shot at being "normal," whatever that means.
Be kind to yourself. Learn to parent that little kid who got a raw deal.
Hugs.
I do not relate to some of the behavior you are describing but I was eating disorders and self-injury.
I do relate to the feeling of wanting to die.
Having something like BPD is excruciatingly emotionally painful. I also relate to isolating.
People do not know how to help because they do not informed themselves. BPD is basically a disorder of the limbic system which regulates emotions....
Hence usually people maybe well meaning say the worse possible things you can say to a person suffering from BPD and are very invalidating.
In fact invalidation is one causes for people having BPD in the first place.
If you are close to someone talk to them and try to explain to them to the point that they become educated on how to be validating and supportive.
As far as evading emotional pain using self-destructive methods...perhaps you can use non self-destructive ones. Like exercise, art,.
That is what you need now. To be able to express your emotions whatever they are and be heard.