Ice forms in the bottom of the freezer and the small hole at the back appears to be full of ice as well.

You may have a problem with the defrost feature. It may be:

1. Defrost heater faulty.
2. Defrost limit switch faulty.
3. Defrost timer faulty.

Someone will have to test those components individually with a multitester to see which is bad and then the part needs to be replaced.

Fridges don't have that many parts that go bad but usually the side by side models have the defroster go kaput. Mine went bad two times in a row. I even got a brand new out of the box model that the defroster was bad! The entire unit was replaced and that replacement unit's defroster went bad twice - the defroster parts would last me about 2 years and then needed replaced.