Maytag fridge making clicking noise

Our Maytag fridge (model MSD2357HEW) has been making loud clicking noise recently. It’s coming from the inside at the top level far back left corner. There seems to be a bit of ice collecting there as well. This is on the refrigerator side.

In the past it also has gotten really cold on its own, so perhaps there’s something wrong with the fan?

What is going on? Thanks.