Hi Loki18,

I’d like to join Merlot and welcome you to the site. I’m glad that you’ve found us there is hope. Many members here can relate with you and offer you guidance and support you’re not alone.
Go easy on yourself and yourself the same compassion that you have your son. BPD is not your fault the causes can be environmental, genetics or a traumatic event.
Read as much as you can about the disorder if will help you with normalizing the disorder and depersonalizing the behaviours. Merlot mentioned different traits.
I can understand feeling worried about your son harming himself not all pwBPD self harm. BPD is a spectrum disorder and not two people are alike.
Do you get help at home? Do you have a family member or friend that’s supportive? You said you got help for your son, have you sought a therapist?
Supporting a Child in Therapy for Borderline Personality Disorder