My experience with traversing the ins and outs of BPD, anything happen before the age of three, that was traumatizing enough to qualify as the BPD label?

The whole notion of abandonment/ rejection/ trauma, as blows to self esteem as a result of traumatic events, i.e., divorce, break ups, job loss, etc.., can seem to spark feelings and emotional fall out, similar to what we'd perceive as borderline reactions, thoughts, behaviours.

I once, feel free to TRIGGER WARNING, this part, had a SA in my teens. Certain SI,SH behavior. My unaddressed trauma at four, not before three. What separates me, from my ex? His trauma was, at age of three, followed by an environment that didn't help him cope with trauma.

These fears of abandonment, fear of rejection, can coincide with other dxs.

You may, also, just not display, not meeting the five of nine criteria.
Have you ever looked at what is a borderline styled personality v. Disordered personality. I found it, in a dsm iv, handbook on personality disorders.

Good to work through, however. When I feel vulnerable, these are the tools I need to keep myself from floating to disorder, type of work through.