My DS normally takes two naps a day goes down fine and really never had trouble going to bed, now it is a FULL ON NIGHTMARE trying to get him to nap, he is sooooo tired, rubbing his eyes but still crying and crying. And really has been doing this for a week or so now. He is crying in the crib right now but I know he needs to sleep. He is almost 6 months...is this normal? A stage?