The way we can differenciate between bipolar II and depression with anxiety is that bi-polar has periods of hypomania.
For a person to be diagnosed as hypomanic, the first requirement is that there must be a sustained, elevated, expansive or irritable mood, plus unusually and persistently increased activity for most of the day over at least four days. The mood and the activity must be observable by others and clearly different from the way you are when you are not depressed. That means there isn't just a big contrast to a depressive state, but there's also a marked contrast to your everyday state when you're not having any bipolar symptoms. Before you can be diagnosed as having a hypomanic episode, you'll also have to be experiencing at least three of the following symptoms - or four if your unusually sustained mood is only irritable:
Sometimes I see client with rapid mood swings in bipolar II and that can look so much like anxiety but the flight of ideas give the bi-polar away.
I dissagree with you psychiatrist I think diagnosis is very imprortant. I am wondering why she is not adding a mood stableliser to your medications. I also wonder if you therapist can call and talk to your psychiatrist. I have a feeling after 4-5 years your therapist would have noticed if you had bi-polar II.