How to go to sleep when fighting with boyfriend?

Me and my boyfriend are in an argument and we were just beginning to talk it through over text until he fell asleep (its very late here and he pulled an all nighter the day before), so nothing is resolved yet, and because of that i cant fall asleep im just tossing and turning thinking about the argument...how do i rest my mind enough to fall asleep? Theres no way to resolve it yet as he is sleeping...