Calm down! You just have to screw it back together. A regular screwdriver works fine, but you can get torque in many ways if needed, e.g., power drill, adjustable wrench on the shaft if it's not round, and torque wrench. There are plenty of bits, bit extenders, and adapters available at any hardware store. Take the opportunity to apply wood glue while you're at it to avoid future problems and squeaks, creaks. /CC