Here is a simple qigong exercise that will help release chest tightness, anxiety, and stress called Pushing the Qi.

According to qi gong (chi kung) and traditional Chinese Medicine anxiety and chest tightness can be caused by stagnation of qi in the chest, heart, pericardium and the liver. Most of the time practicing a simple qigong breathing exercise like this one can dissipate that qi stagnation.
Of course you want to make sure that you consult with your doctor or professional but you can safely add this qigong exercise to your daily routine to help manage and reduce stress and anxiety.