Hi Unforgiven-
"Psychopath" is an obsolete term as far as the clinical folks go, that combination of traits are now called Antisocial Personality Disorder (ASPD), which is distinctly different from Borderline Personality Disorder, although everyone's different and lots of folks have comorbid, meaning at the same time, disorders.
Here's the official description of
ASPD and
BPD; you might read through them and see if they shed any more light.
And in the end the official diagnosis doesn't matter as much as his behaviors and how they affected you. Please read through and let us know what you think. Take care of you!