Hi Misssy2. It could be one, some, all, or none of what you listed above. Sometimes it's just nature or nurture. It could be anxiety. It could be all kinds of things. It is, however, something you might want to discuss with your therapist and psychiatrist. Definitely having a short temper/fuse can be quite problematic in life, so it is best addressed.

I do not believe in the idea of "bipolar personality". Bipolar disorder is not a personality disorder. It is a mood disorder. Even within bipolar disorder, there are all kinds of personalities for various reasons, both based on nature and nurture. I'm not even that thrilled with the idea of labeling personality disorders as "personality" disorders. It's not altogether fair, I don't believe. There's surely a lot more to it, than that.