I have to be up in 4 hours and have yet to fall asleep. Just laying here in bed wide awake. Why…

I have to be up in 4 hours and have yet to fall asleep. Just laying here in bed wide awake. Why can't I just sleep. Like seriously the days I have things to do I can't fall asleep but the days I have nothing to do I go to sleep just fine. For crying out loud my husband went to work already and is home past out and he works night. My daughter is crashed out but me nope my body just doesn't like me right now.