When you are in the middle of a panic or anxiety attack there are so many thoughts cluttering your head and it becomes difficult to sort fact from fiction, however our brain is a wonderful thing, and if we distract ourselves and allow our sub-conscious to take over we are often able to regain control of our conscious thoughts.
One of the most effective techniques I have found during a panic attack is to watch repetitive animations. One of the first animations I found to help me with this is quite an internet famous one.
I do not know who has the original copyright for this, but whomever it is I owe a huge debt of gratitude. They have no idea how many times I have watched it during an anxiety attack.