whrilpool gold not cooling or freezing

End of September 2012 I discovered my bottom mount freezer had completely defrosted, I was leaving for the weekend and didn’t have time to address. When I returned it was frozen so I thought the door was ajar. In January 2013 it happened again and I pulled the fridge from the wall and cleaned everything and it worked. Now it is 6 0r 7 months later and it happened again. I pulled from the wall and cleaned and it worked for a day and then everything, freezer and fridge, warm and everything melted. The compressor sounds like it is on but I can tell by the sound it is working intermittently. Could it be the compressor starting device, or is the compressor going out. All of the fans seem to be working normally.