You beat me to it! OP, my younger sister went through similar stuff in middle school and high school. Back then everybody just thought my mom was too easy on her-- you know, all she needed was a swift kick in the pants to snap out of it.

Back then, my mom didn't know that what she was seeing was the beginnings of a serious anxiety disorder. My sister never got any kind of treatment until she was well into adulthood. Her high school years were pure torture. Her adult years haven't been much better. She tried to kill herself last year.

NOW they're listening to her and things are getting better. She's 45.
OP, I urge you to get yourselves into some family therapy. Forget what the ped said--what a maroon! I hope you fire him. Kids go to counseling for lots of different reasons. Just growing up in a home with a sibling who has Aspergers would be enough reason to touch base with a therapist(I have a child who is very low-functioning, so I see first-hand what these siblings go through.) Call a therapist who has experience with adolescents and anxiety.
And since your ped doesnt seem to willing to help, think about taking her to see a psychiatrist. Don't faint! There, there! It's not what you think. A psychiatrist manages medications, which she could very well benefit from . Meds don't cure anxiety, but they are a tool with which to manage anxiety.
Anxiety and mood disorders are rampant in my family. I suffer, my mother suffers, two sisters and a brother suffer. And that's just my immediate family. There are 11 first-degree relatives that i can count who have diagnosed mood disorders in my family. Without my meds I couldn't even leave my home. I can't go to church or cross a roomful of strangers. I can't look men in the eyes.

With meds I can be the person I have always been--friendly, compassionate, loving and kind, instead of a freaked out mess. Your daughter needs you to believe her--it really is as bad as she thinks it is. She needs to know you will move mountains for her, even if you have to try some things you've never done before. MOm, you have the opportunity to show her the way. Don't be afraid. You might be saving her life.