Freezer & Fridge Both not cold anymore

I have the good old GE side by side bad boy that I have been seeing all types of problems but not my problem. Both the fridge and the freezer have slowly stopped cooling. I noticed because my Milk came out in a chunk last night. Freezer has some ice on the back wall. I don’t see a thermometer in there. I took it apart this morning and the compressor or condensor seemed to still be humming at the back, but the normal sound of the freezer and refridgerator is not there anymore. Still making Ice and water, but things are slowly melting. I am looking for a manual for this thing some where. GE has a terrible website, when you search for the manual it just puts up a 404 error or something.
Is there anything I can do to find out what part I need before GE comes here on Wednesday. I would like to solve this myself. I dont want to manually defrost the thing unless I have to because I still have food in there and it will make a mess. Any ideas would be great thanks.:confused: