You need to defrost the fridge periodically, the way we used to have to do it from the 1940s through 1960s before "frost free" (actually periodically hidden defrosting) refrigerators became the norm for residential sales.
Actually, more recently, since most "dorm" and "bar" fridges are not self defrosting, nor was the Eastern European refrigerator supplied with my $4500 per month luxury apartment in Beijing, at the beginning of the 21st century.
You've gotten to accustomed to a luxury. Defrost your fridge when it frosts up, takes no more than a couple hours.