Breathe
The breath is a powerful tool to sooth and calm our nervous systems.
Try focusing on your breath and conciously breathing in and out evenly, for about 4 seconds in and 4 seconds out. See how this feels after 5 rounds.
See if you can extend your exhale, even if that is for 5 or 6 seconds. See how this feels after 5-10 rounds.
A longer exhale helps activate the parasympathetic nervous system, which brings calm to the body and mind.