Psalms 127:2 It is vain for you to rise up early, To retire late, To eat the bread of painful labors; For He gives to His beloved [even in his] sleep. (NAS)
Sleep is as necessary to life as is eating. It allows the mind time to process the days events, gives the body opportunity to rejuvenate, the emotions are given some space to sort themselves out, so it is good for body soul and spirit. That is, if you have satisfying sleep. Without it we are as grumpy as two year olds, and we find that because we had fitful sleep we still have the same problems, but now we have even less strength to deal with them.
Charles Spurgeon described the dynamics of a stressed out mind at bed time, with word pictures better than I could ever attain to:
"You imagine if you fix your mind upon a certain subject until it shall engross your attention, you will then sleep; but you find yourself unable to do so. Ten thousand things drive through your brain as if the whole earth were agitated before you. You see all things you ever beheld dancing in a wild phantasmagoria before your eyes. You close your eyes, but still you see; and there be things in your ear and head, and brain,which will not let you sleep."
Hard work and hard worrying will have you eating what the text above calls the bread of painful labors. If you never learn how to process stress you will wind up sleepless in Seattle, turning to drugs, cranky, wore out, and nigh on to a nervous breakdown.
The bible has some sound advice that has stood the test of time, and helped many a weary pilgrim. First it tells us that worry is useless. (Mt. 6:27-33) Worry is not capable of doing anything to improve your situation, all it can do is rob you of strength, and take the wind out of your sails. In short it makes things worse.
The second piece of advice is to cast your care upon Him, because He cares for you. (1 Peter 5:7) I am not a very good fisherman. Whenever I cast a line out, I pull it in a few seconds later and see if I caught anything. That is not how its done, I know it, and that is why I hardly go fishing, I don't have the patience for it. Being aware of that part of my personality has helped me to realize I can't be the same way with prayer. You can't pray and then 2 minutes later say, "where's my answer?" That is not how it works (usually). Like the song says, take your burdens to the Lord and leave them there. Easier said then done, unless of course you REALLY DO TRUST the person you are leaving them with. Keep your fire burning, get rid of the weights that would dampen it.