Very interesting that you're questioning about this. I was wondering the same thing. Since I started therapy bpd has always been in the picture and I have been diagnosed once, but then the therapist after that one said I definitely didn't have it. I have that poor self image as well but for me it can turn to a self overestimating in my good episodes. I also feel that I am barely really happy, but I have my times of a few weeks that I really feel pretty happy (and get a little speedy I guess). Just coming back from my first time of really trying to get a diagnoses and have them put me on meds because I am going crazy and the therapist said I might have borderline of bipolar or both. So seems to be possible anyway to have both.