Welcome to PC JackUK - the first step for you would be to get a doctor check up with blood work, to rule out physical problems. If that comes back good then your doctor can explore the psychological side. One thing you can do is, slow deep belly breathing and do this any time you start to feel stressed. Do this also a couple times a day - take ten minutes - inhale slowly using your stomach muscles ...hold for a few seconds...then exhale slowly. Keep doing this until you feel more calm. If it turns out you're having some anxiety and panic issues - learning not to fear them helps a great deal.