It helps my daughter calm down when her anxiety is off the charts. The key is practicing it when you're not having a panic attack enough so that when you are highly stressed, you can drop into a calming space quickly. Worth a try.
If you're willing to try alternative therapies like the butterfly hug, you might also look into tapping (emotional freedom technique) for anxiety. You can find it at ect.mercola.com.
Sending you thoughts of peace and healing