All your worries and anxieties now are tired nerves.
When a worry appears, drop it. If it appears again, drop it again. And so continue to drop it if it appears fifty or a hundred times a day or more.
If you feel like crying, cry; but know that it is the tired nerves that are crying, and don't wonder why you are so foolish,—don't feel ashamed of yourself.
If you cannot sleep, don't care. Get all the rest you can without sleeping. That will bring sleep when it is ready to come, or you are ready to have it.
Don't wonder whether you are going to sleep or not. Go to bed to rest, and let sleep come when it pleases.
Think about everything in Nature. Follow the growing of the trees and flowers. Remember all the beauties in Nature you have ever seen.
Say Mother-Goose rhymes over and over, trying how many you can remember.
Read bright stories for children, and quiet novels, especially Jane Austen's.
Sometimes it helps to work on arithmetic.
Keep aloof from emotions.