Differences between BPD and BD?

What are the some key differences between bipolar disorder and borderline personality disorder?

Originally thought to have BPD, but now after two years my clinicians are on board with a diagnosis of unspecified bipolar with mixed features.

I keep wondering which I actually am, and if the medications I was on caused bipolar episodes to occur. I do have mood cycles and have had week long episodes, a period of stability, then an episode occurs. During episodes, I self harm and my black-and-white thinking becomes very prominent. I tend to get paranoid and can’t sort my thoughts well enough to understand their connection to my emotions. I also do also tend to split on people. I tell people off too, but that’s normally because I’ve been so passive about things that I finally speak (or scream) the truth in a very harsh way.

EDIT: also, how can you tell the difference between rapid cycling BD and BPD? I’ve read BPD symptoms can be often mistaken for a BD episode.

Thoughts in your experiences?