Try to calm yourself down. Here are a couple of techniques you can practise right now:

1. Deep Breathing: Put one hand on your chest and the other on your stomach. Take a deep breath in and make the hand on your stomach move and the hand on your chest remain still. Takes a bit of practice, but with practice it gets easier. Take a deep breath in and hold it for a count of three. Then breathe it out through your mouth and count to five before taking the next deep breath. This prevents you from hyperventilating during an attack. You need to practice this breathing daily for at least ten minutes so that it becomes an automatic response. Eventually, it comes secondary in nature.

2. Muscle relaxation: Starting with your toes tighten the muscles for thirty seconds to one minute until they start to ache. Then completely relax the muscle group letting it go limp like spaghetti and repeat the process until you know how to relax the muscle. Repeat this with all the muscle groups- fingers, hands, arms, shoulders, neck, legs. Practice this relaxation daily. When a panic attack hits, you mentally check to see which muscles you have tensed up and then relax them.