ok so you did not clear the largest portion of the ice.
If you remove everything out of the freezer and remove that rear interior panel I think you will find it just covered in ice to the point that the fan may be blocked with the ice.
Which would mean the unit has a defrost issue.
And if it is packed with ice and frost lets run a manual defrost cycle to see if it will defrost .
here is howto manually advance your unit into defrost .
But do not do this until you remove that rear interior wall and look to see if the ice is blocking the fan blade from turning .
Forced Defrost Mode: The forced defrost function is performed using the refrigerator display and keypad.
Enter the Forced Defrost Mode by performing the following sequence of events:
1. Hold the refrigerator door light switch closed.
2. Press the Refrigerator Temperature DOWN /- keypad 3 times consecutively. Note: The 3 keystrokes must be consecutive and within 10 seconds.
3. Release the refrigerator door light switch.
4. The control will display F- d to confirm entry into the Forced Defrost Mode.
5. Entry is confirmed by pressing the Refrigerator Temperature DOWN /- key once more. The unit is off and in the Defrost Mode.
Note: All control functions will be turned off (Compressor, Defrost, Evaporator Fan, the damper will remain in its current position).
6. The control will default to the short run period test.
Note: You can toggle between the S Short and L Long test mode by pressing the Refrigerator Temperature UP /+ Key. Long Test mode is used for factory test and should not be used in the field.
7. Once the desired mode is displayed, confirm the forced defrost by pressing the Refrigerator Temperature DOWN /- Key once. The defrost will begin immediately and the display will return to a normal operating display with set point values.
8. Close the Refrigerator door(s). You are in the defrost mode. Note: Forced Defrost mode can be exited at any time prior to step 7 by closing the Refrigerator Door(s).