On thing that has helped me calm down a racing mind is a coloring-book (!). They have amazing ones made for grown-ups, I personally have one with beautiful mandalas. But there are all sorts of designs. When I can`t sleep and my mind is running a marathon, I get up from bed, make me a cup of decaf, and sit down at the kitchen-table and do my art-therapy. It is good to distract my mind by consentrating on something very practical.
Knitting has the same effect for me. These are two easy, calming activities that helps me a lot.
Music helps a lot, but sometimes not even that calms me down when I get into the stage you are describing.