[Spartan]

I find that if I am tired then I often feel more anxious or have a harder time controlling anxiety. Also, once I get into a pattern of acting anxiously around certain people, groups of people, or even places, then I get into a habit of doing so which is hard to break.

Sometimes I feel completely confident and can discuss ideas freely to a seminar class of 20 people. Other times I feel like a nervous wreck when speaking one on one. It's weird!

edit: I noticed that you said you felt short of breath. I have been told that many of the anxious symptoms can be alleviated if you change your breathing. When someone feels anxious they start to breath faster and only through the chest - this actually causes the symptoms of anxiety. When you next notice you feel anxious try to become conscious of your breathing, then control it by breathing slower and through the stomach instead of the chest. This should help alleviate your anxiety.