Some people, like myself, can do it alone. Others may need professional support. I also would like to note here that there are ways in which Borderlines self-harm. I also would then devalue the world around me, which was my own feelings of self-hate projected out again because as a Borderline I had no boundaries, I was not indivduated and I did not know, at all, where I began and ended in relation to others and to the world around me. You do not have to self-harm to survive.
Borderlines do what they do to survive.
Borderlines do what they do to protect themselves from the intensity of the reality of all of the pain that they are in. Borderline pain is VERY real.