I have had rounds of a similar thing myself. Laying down on the bed and covering head to toe with a blanket helps me. I wonder if the effects similar to breathing into a brown paper bag like they do on tv.
We're trying a calm down thing at the house. I saw it when looking up something for someone else. We're using for self-control over anything you need to get control of yourself over. Maybe it helps anxiety too. Tell them to squeeze all the juice out of an orange with one hand, then with the other, then with both hands. Drop the oranges on the floor and shake out both hands. Rinse. Repeat if desired. Until you feel like you're in control. Practice at at random as well. In addition addressing the underlying issue, you could try this approach because it seems like it would help in so many situations and because it's simple.
