I have read a research paper(PhD) that concluded that childhood trauma specially prolonged chronic invalidation leads to development of BPD.I have had chronic invalidation almost my entire life.I have been paying attention to my own feelings and behaviours.I do have grief and sadness that seems tobe always there, but no symptoms of BPD.I have these feelings like I donot know who I am,what I like or donot like,what are my life goals,what do I want to do,things like that.I am thinking that is what feelings of emptiness are.Its like you don't exist.