Whether you are or you aren't, the symptoms you just described are like mine for the past 4 weeks. I've been manic or mixed according to my dx. I think one of the key differences between BPD and bipolar is the length of time in one state or the other. The manic episode at least a week long (or mixed with both depression and tons of energy, impulsivity, insomnia, etc.) and usually sandwiched between 2 or more weeks of depression on either side of the episode.

BPD has more relationship issues which may or may not be explained by bipolar related actions. I think the idealizing and then totally devaluing people in one's life is a key sign to BPD. It's more like whims and people are all for you or all against you. You can be both bipolar and have BPD, and they have overlap symptoms with mood swings. I just find that other than rapid cycling or mixed days, BPD seems like the moods swing a lot more often.

Sorry if I've already said all this. I'm kind of tired and can't remember things very well right now.

Wish you the best in your treatment and search for hope and treatment of whatever's causing your symptoms.