If you struggle with getting a good night sleep, I have lived that nightmare. The single most helpful thing for calming my nervous system down and helping me sleep is the Legs on the Wall yoga pose. I have to admit, if I wake in the middle of the night, I will often do it from bed, simply taking the pillow out from under my head so I can lie flat and put my legs straight into the air. While I do not recommend that you follow my “shortcut”, the instructions and information on the practice are found in this link. I have found it immensely helpful.
Here is my new favorite guided meditation by Tara Brach, “Relaxing Back Into Natural Awareness .“ Give her a listen!