I am going through a similar experience as well. My story started about 5 months ago, when my anxiety first went full-blown "symptomatic" in the span of about 5 minutes. I felt like I was crawling out of my skin. The entire world was hostile and alien, including my house. The physical symptoms (shortness of breath, one foot feeling "different" than the other, head pressure, nausea, insomnia, thirst, dry mouth and lips, etc.) and emotional symptoms continued relentlessly for about 2 months. I've been to every specialist I can get my hands on (pulmonologist, neurologist, sleep disorder docs, dermatologist, cardiologist, GI doc) and had a whole series of tests (MRI's, CT scans, EMG's, EKG's, blood work, sleep studies, you name it) without any official diagnosis other than anxiety. After I had all of my testing done, I went so far as to sit down with a different primary doctor for a second opinion. Again, anxiety. On the advice of my many doctors, I started to see a therapist. When the behavioral office first sat down with me, I got lucky and had the head of the department (and this is a huge and well respected teaching hospital) sit in on my session (I was told this was abnormal; I think he was checking up on the intake counselor). He confirmed that he felt it was anxiety and that nervous system issues can take many, many forms. He also advised that I not be afraid of meds.
And yet, with all of that work done on me, I still feel like it isn't (entirely) anxiety. While some of my symptoms have gone away (my emotional symptoms are almost normal again), a few remain just as strong as they ever were (mainly my foot and occasional shortness of breath). The therapist I was assigned to thinks that I am afraid of my physical symptoms, which in turn creates more physical symptoms. It doesn't really matter what stresses in my life first caused everything to go symptomatic, but once the flood gates open...they really open. They are suggesting that I start on Lexapro to break the physical symptom loop while starting CBT to stop the negative thinking. I'm trying to keep a journal to identify my "triggering events" but find it difficult to connect a thought to the symptom since the symptom is pretty much always there.
I guess my point is that you are not alone. Anxiety can do a ton of strange things if you let it.