Fridge keeps on freezing everything inside of it

This refrigerator only has one thermostat located in the fresh food compartment it is designed to activate the sealed system (cooling) until it reaches approximately 37 deg f in the fresh food compartment. The damper controls how fast the cold air can move from the freezer compartment to the fresh food compartment. Allowing you to control the temp in the freezer by controlling the flow of cold air to the thermostat.

You have one of two problems.
#1 your thermostat is no longer opening when it achieves set temp. fix = replace thermostat pn 61005798 $35
#2 your damper arm or assemblie has broken. Fix = Replace damper or broken arm and actuator.
damper assembly pn12001377 $44
damper actuator pn 61002000 $2
damper arm pn 61001999 $2

thermostat actuator arm damper arm

damper assembly both pics