One of my worst problems when sitting an exam for me is the physical symptoms of high-intensity anxiety (pounding heart, increased breathing rate, shaking hands ect). It would worsen the anxiety and make my mind race to the point that I couldn't answer the questions compared to if I was calm and level-headed. My doctor prescribed me propanolol to take before the exam which completely irradiates these physical symptoms. Might be worth a shot for you.