Hi kate, I too have some anxiety issues, and I've found a good way to deal with them.
First off, take it easy!! Things generally aren't as bad as you think they are!
Second of all, get your mind into a state that you can think clearly in
Symbio has the right idea here.
When I feel anxious due to a thesis paper being due or other stressful situation, I sit in a dark room and listen to pink floyd, namely the Dark side of the moon album. Although this may not work for you, try it. Try to disconnect your mind from the rest of the world, and concentrate on some part of the music other than the vocals. Thats why I love pink floyd, because there are an infinite number of things to concentrate on!!!
Dealing with this from a physiological standpoint, also think about what you have ate in the past 6-12 hours, this may be adding to your stress. I thoroughly believe in Bio-psychological solutions. What is wrong in the mind can be fixed partially by the body. I do not, however condone the use of excessive psychoactive medication.
Symbio also had it right in another aspect, list your stressors and their severity level, and find out what is really bugging you. I find this to be the best technique. I list out what is making me nervous or anxious, and rate them on a scale of 1-10. After doing this I analyze the list, and find out what I can do to take out the little things that are adding to the stress. Once all that rubbish is out of the way, you can think straight and find out how to solve the big issue.
Here is my own personal example.
I have a 9 page psychology thesis to write and it's due in less than 2 days and I haven't started yet. (Trust me its the way i write essays, and I always get A's when i do it that way)
My apartment is full of empty coke cans, and I need to take out the trash.
I have a pile of clothes the size of Everest to wash and organize.
To solve this problem I clean up the apartment, take out the trash, and put all the dirty clothes into one room where I cant see them.
After all of this is done I can concentrate on the big issue, in a clean, structured environment where I can think and not worry about other stuff to do.