Hi Katie,
Relax, and dont worry, what you are having is common with anxiety sufferers. I know how it is to need to know that someone else feels the same way too. Its very comforting to know that you are not alone.
I am very familiar with the headaches, the "fuzzy" feeling,the congestion, and many other physical symptoms caused by anxiety. In fact I have the same thing today. I have had panic and anxiety since I was 19 years old and i'm 31 now, so unfortunately I have lots of experience with it. I still write in regularly when I have a new symptom just to reassure myself that i'll be Ok and others feel the same way.
When I was first diagnosed with panic and anxiety I just could not accept that it was a "mental" condition. Even though I had been to several doctors and had all kinds of tests, I just couldn't believe that I wasn't physically sick. Everything went through my mind - brain tumor, cancer, thyriod, you name it I thought it may be what was wrong with me. I was convinced that I had been misdiagnosed. I was amazed when the meds got into my system and started working, they were actually helping and I was starting to have alot more good days. Its really amazing how your nerves can make you feel so sick.
This site has been so helpful to me. I was really glad when I found it. We never have to feel alone as long as we have this place to come to.
Good Luck! I hope you feel better soon.
Samantha