I'd go back to my pdoc and discuss your symptoms. You could be suffering from bipolar II, rapid cycling (I'm not a professional, so please don't quote me), but that's what I am like and I am BP II. I can go from high to low and back to high in a matter of hours.
And if your dx is depression, you're probably only on an anti-dep (Correct me if I'm wrong) which would cause a BP patient to be pushed into mania, or hypomania, which could be what you are experiencing when you feel ok.

A lot of people that are dx'd bipolar, are first dx'd with depression.