Please advise.

In answer to this question there are several breathing techniques you can use to calm yourself down. There is a yoga breathing technique called "alternate nostril breathing" this is best for cases of high anxiety and panic attacks. Any technique to draw you back to the present moment will decrease these symptoms of anxiety. You can also count by inhaling for 4, exhaling for 4 counts. Utilize your 5 senses, "in this moment what is something I can see? Something I can hear? Something I can smell? Taste? Touch, etc." Find something that you can utilize in 5 seconds to decrease this behavior.

It is also important to identify your triggers- when are you getting these panic attacks? What time if day is it? What is a thought going through your head? Try to track the behavior of anxiety/panic and you will be able to identify a pattern in your behavior. Once you identify what causes your "panic" you can become more aware and develop coping skills for this situation. 

Aside from the breathing technique mentioned above, 10 minutes of meditation a day is great for calming and refocusing the mind, or developing a yoga practice. Yoga is about connecting the breathe with body movement and is seen as a moving meditation. A regular practice can also help with decreasing symptoms of anxiety. 

Another great technique is just to acknowledge that anxiety is there. For example, "I'm starting to feel anxious. I recognize I am feeling anxious, but in this moment I am choosing to not give this thought power over my feelings and emotions." Accept that certain situations are out of our control. The more we try to control situations that we have no control over, the more anxious we tend to become. Always realize that we will have moments where we become anxious, or depressed but internally we can develop skills to handle these situations. Therefore, the direct process would be identify "what is making me anxious?" Implement a breathing technique or a coping skill in this moment to decrease symptoms of panic, and then recognize "I don't have to give this thought the power time affect me in this moment."

Hope this helps!