Why is falling asleep so hard?

I have no idea what happened to my amazing sleeper girl. For the past 6 months she's been awesome about going to bed, but we're back to the days of taking an hour to fall asleep. There's screaming, kicking, jumping, yelling oh and did I mention screaming? Her favorite things to scream are "mommy, rock a minute" and "daddy rub my back". Not only has she had a horrible time falling asleep at nap time and bedtime but like clockwork she's been waking up between 3:30 - 4:00am. It usually takes her about an hour to calm down and fall back asleep again...it's exhausting and frustrating. I love you Paige, and you need to give mommy and daddy a break...we're beat!