Everyone experiences stress and performance anxiety. Nobody likes it, and some people suffer terribly from it. Some stress is necessary for our survival. As cave dwellers, stress and anxiety caused by external threats were excellent drivers of survival behaviours. The trouble is, in the modern world, from your brain's perspective, there are many more perceived threats and the pace of life doesn't allow sufficient downtime between "threats" to recover perspective and get yourself back to a place of choice: whether you are going to remain in control, or be controlling of people or things in the world outside.