It is called Alexithymia, it is a difficulty in recognising and describing one own emotions. 85% of people with Asperger's have Alexithymia. I exhibit this trait myself.
For example, in 1987 I visited a doctor for panic attacks, but I could not explain my emotions to him. Thus he did not understand that I was scared, that I was experiencing panic attacks. I was treated for a heart condition and he sent me to see a cardiologist.
http://en.wikipedia.org/wiki/AlexithymiaThere is currently an edit war happening on Wikipedia that was unintentionally started by me, I added information that included several papers that show that Asperger's and Alexithymia overlap. This is the bit I wrote (its a little modified now).
"Research indicates that alexithymia overlaps with Asperger syndrome. In a 2004 study, Uta Frith reports that not only does this overlap exist, but that at least half of the Asperger syndrome group obtained such extreme scores on the Toronto Alexithymia Scale (TAS-20) that "they would have been classified as severely impaired."[27] Fitzgerald & Bellgrove pointed out that, "Like Alexithymia, Asperger’s syndrome is also characterised by core disturbances in speech and language and social relationships".[28] Hill & Berthoz agreed with Fitzgerald & Bellgrove (2006) and in response stated that "there is some form of overlap between alexithymia and ASDs".[29] They also pointed to studies that revealed impaired Theory of Mind skill in alexithymia, neuroanatomical evidence pointing to a shared aetiology and similar social skills deficits etc."
Fitzgerald M, Bellgrove MA (2006). "The overlap between alexithymia and Asperger's syndrome". Journal of autism and developmental disorders 36 (4): 573–6. DOI:10.1007/s10803-006-0096-z. PMID 16755385.
Hill E, Berthoz S (May 2006). "Response to “Letter to the Editor: The Overlap Between Alexithymia and Asperger's syndrome”, Fitzgerald and Bellgrove, Journal of Autism and Developmental Disorders, 36(4)". Journal of Autism and Developmental Disorders 36 (8): 1143–1145. DOI:10.1007/s10803-006-0287-7.
I had the same experience as you with panic attacks. I ended up being checked for cardiac problems as well. I only knew that I felt like I was dying.