I have bipolar and was also told I have BPD "traits" by hospital psychiatrists once during an inpatient stay for a mixed episode, I am not actually sure if BPD is accurate for me or not, I certainly have some of the symptoms but they also seem to overlap with Bipolar - for example I get impulsive but only when I am manic, I don't really have issues with maintaining relationships or feeling abandoned but I do self harm, although 99% of the time the self harm is related to my eating disorder... It's complicated LOL. I guess just speak to your doc about it and see what they say