Should I try to separate my 'true' personality from the anxiety?
Should I try to form a 'medium' between the two?
Should I include my anxiety as part of my personality?
Should I try to imagine various forms with an anxiety disorder and go from there? (IE, say, a toucan with anxiety)
Well, personally, I would choose the form that fits completely ignoring your anxiety. You're probably not a loud, boisterous kind of person (though I could be wrong) and usually personality traits complement each other. Obviously you're an 'anxious' person, so something of that could be included, but obviously you are so much more than that. My friend has anxiety, and would take a spider form if she was a daemian, all the traits fitting her to a T, it doesn't say anything about being anxious, but the other traits complement that and so it serves as an individual form, not at all dependent on anxiety, but one that includes the trait - as it is a character trait.
Ignore it and find an accurate form, and those traits will most likely include a nervous demeanor! (which, is not a bad thing at all when you look at the remarkable traits found alongside it)