Refrigerator and Freezer is warm

I have a Kenmore top freezer refrigerator that is running warm on the refrigerator part and the freezer. It will make ice but it takes forever. I have noticed that my freezer inside the back wall is icing up and I have had to defrost it more than once. Once it is free from ice, it runs fine for about a month. I have searched this site for my model number but there does not seem to have any info on it. Can anyone please advise me? Thank you