> My psychiatrists have flirted with a bipolar diagnosis but ultimately they think it’s standard anxiety / depression.

I hear that very often, especially from the people diagnosed around 30-15 years ago. I can't get the feeling that this is just an easy excuse to cover inability to find a real cause. I have no study to back it up, just my experience, but I've yet to see a person who has an anxiety just like that. It is an effect, not a cause. You can't treat an effect an just happily ignore the real reason. I am biased by the people I around me, sure, but I would say, very often the cause is being different (even if only slightly) and difficulties to find yourself in the society.

(edit typo)