How does BPD present with you?  I feel like I am BPD but don't have the stereotypical symptoms which are basically the symptoms as they look when a white middle-class person has it (to clarify: the DSM basically describes symptoms in the U.S. as they present when a white middle class person has the disease because it's exactly that demographic that is most likely to have access to mental healthcare and because most mental healthcare practitioners in the U.S. are white).  

For example, I don't make frantic attempts to avoid real/perceived abandonment (apparently, the de rigeur requirement for BPD) and I don't self-harm.  

In my twenties, I did tend to idealize certain people, but I eventually grew out of it.  I also did and still have some problems with black/white thinking (splitting), but I attribute that largely to growing up in American culture where that is taught (especially in the public school system).  I'm not exactly sure I "split" more than most Americans do.

What I do especially have problems with, to this day, is:
-- rage/anger/vengeful thoughts
-- depression due to constant negative thinking
-- rumination/obsessive thinking
-- difficulty forgiving and forgetting ... just letting things go
... in other words, the usual emotion-dysregulation stuff

NOTE:  I was born and raised in the U.S.  Grew up with white people and white friends.  My parents split when I was 5 and I was raised by a BPD mother who never received any kind of treatment for the disorder.

EDIT:  I also have problems figuring out who I am and having a crystallized personality, which most people do long before they are my age (I'm in my 40s).  I still cannot figure out what I want to do with my life and have had many job changes and wildly diverse career pursuits.