I haven't slept in four days. How can I fall asleep?

Eat then listen to soft music when you lay down. You may also want to get checked by a doctor because this could be insomniac-induced sleeplessness. If something in your brain is keeping you up, therapy may be something else to look into. Another thing it could be is a simple hormone rush which shouldn't last any more than 7 days. Hope this helps and I hope you can sleep!