My air stopped being cold it still blows and is not all the way hot air, it is on auto, but won't cut off, and the thing outside is very cold. What is this

my air stopped being cold it still blows and is not all the way hot air, it is on auto, but wont cut off, and the thing outside is very cold. what is this
It won't cut off because the machine haven't meet the thermostat's set point. The thing outside (condenser unit) is very cold, if it forming ice ; it an indication of the machine doesn't have enough( leak) freon