consider: could an eating disorder cause the fantastic mood swings and mixed states you experience? (hint: no.) Bipolar makes no sense in the beginning, it's such a broad scape of symptoms, and the overlap with other dx's is confusing indeed. But you, my friend, are so classically bipolar no right minded clinician could treat you otherwise right now. Hang in, and hang on, it all takes time, but you will find some room in there soon enough.
I know what you mean though, really, it might be the most chameleon like disorder of them all.
These are good questions that all of us with bp have asked. I'm glad you're asking them.
It's so good you stayed on.