Hi, there are many possible causes behind this. You might just be tired, or there might be an issue like uncomfortable pillow. You'll have to do a bit of trial and error to find out. If nothing works, then it might be insomnia. But I'm sure its nothing to worry too much about. Temporarily, you can take melatonin capsules an hour before going to bed so that you can sleep peacfully through the night. Melatonin is a widely available drug and you can also find it online on websites like https://www.vitaminexpress.org/uk/melatonin-supplements. Or you can simply do a google search for melatonin capsules in your country and a bunch of products will pop up. Hope this helps.