About 2-3 weeks ago, I also started having anxiety problems. Mine is infact,'Post Traumatic Stress Disorder', and before I was even diagnosed, I had no appetite. I'd lost 7 lbs, not really realising I wasn't eating. After a while I had to force myself to eat, and saw my Dr. who diagnosed the anxiety disorder.
I strongly recomend you see a Dr. to see if they can diagnose what the problem is, and proscribe you something if needed. It is relieving to hear the words from a professional, letting you know exactaly what the problem may be.