I have this ALL the time:( My only anxiety symptom, and one of the worst in my opinion. Breathing exercises don't work for me, they actually make me more anxious and lightheaded. I used I run and cannot anymore. It also effects my driving, as that is a huge trigger for me. I had this same symptom about 5 years ago and went away when I started buspar. Tried it this time and didn't work. Dang.