Okay, if you are struggling with a tight chest sensation, you will benefit from learning to breathe productively. It's very common when anxious, to breath rapidly and in a shallow manner. This can result in hyperventilation and thoratic (chest muscles) fatigue. The chest and abdominal muscle get tight, not allowing you to take a good deep breath comfortably, thus making the whole cycle worse:(
Here are a couple of links that teach some breathing and relaxation exercises, and I'll post my favorite 'The divided Breath' below...
www.ehow.com/video_4405003_breathing-exercises-panic-attacks.html
www.stress-relief-exercises.com/
www.psybersquare.com/anxiety/panic_relax_I
Okay, my favorite is this one, it takes some practice though. When I first started, I could hardly do one!
The Divided Breath:
Imagine your lungs as having 3 parts. The bottome third, the middle, and top third. On the inhale fill the bottom third first, then the middle and finally the third. Make sure that this is one continuous breath, but divided, with a slight pause in between each third. Hold the breath in for 3-5 seconds if possible. Exhale in reverse. First blow out the top third, then the middle, and finally the bottom third of your lungs until all air is expelled. (remember the pauses) Repeat several rounds for a toatal of about 10 minutes. Practicing this every day will not only give you control and structure to your breathing, it will strengthen and loosen the thoractic muscles, allowing better, more productive breathing, and relieving the chest tightness!
Good luck, and remember to pracitce everyday whether you're stressed or not, that way when anxiety really shows up you'll be ready:)
Scaredy Cat