Why Won't He Sleep?

These days Austin will not go to sleep without freaking out. He wakes up during the night flipping out as well. In the morning he will not sleep in at all. He's averaging about 9 hours sleep per night and often will only napfor about a half hour or 45 minutes. It's totally draining; it's like I have an infant again. Listening to his screams and constant crying is just torture. I don't know what is going on with him. I know it's just a stage, but the past week has drug on like it's been a month.