Have you considered asking about Borderline Persobality Disorder?

It's very rare for someone with bipolar disorder to cycle that rapidly, but people who appear to cycle that rapidly may have Borderline instead. The two disorders are similar in some ways.

I obviously don't know what you have since I'm not a doctor, but Borderline is worth looking into

Best of luck!

Edit: http://www.nhs.uk/Conditions/Borderl...roduction.aspx