This could be your thermastat going out. It can be replaced if you call or look up the part on the internet or call you- FIX- IT appliance store #9919 Garland rd. Dallas,Tx.(214) 321-7054.
Sounds like it could be the txv valve and that valve is letting in to much refrigerant, into the evaporator. Either a repair man or a new fridge for this one unless you are rses certified.
Turn the dial 1/2 way in the other direction. the lowest setting in reality is the coldest setting. this is why everything froze up.