Hello. I realize your post was some time ago, but I thought I would respond to you with what I understand, given that I've been dealing with extreme anxiety for years.
According to anxietycentre.com, which is a really wonderful place for information, anxiety is a result of a hyper stimulated nervous system. This hyper stimulation occurs from a repeated stress response in the body, due to dysfunctional thoughts beliefs, whatever, in response to life.
My actual therapist describes anxiety as this state of unresolved conflict within oneself.
I, personally, agree with both.
Where I struggle is with changing all of this, even with all the information available in the world on the subject.
I would say, yes, there are emotions behind it.
Let me add, too, that when you have an anxiety attack (I differentiate these from panic attacks, I don't know if you do), you're thinking brain is offline. And all the stress hormones are coursing through you, so I think to would be very hard to identify any emotion at that time. Its like you're beyond that point once you reach anxiety and the focus has to be on calming the body. I don't know.