What you need to do is clean the condenser coils. These coils are what removes the heat from your freezer and must be allowed to transfer the heat to the air in order for the refrigeration cycle to function.
These coils get clogged with dust and are choking your system to the point that it is having a hard time maintaining the set temperature.
Find the coils on your system, usually under the freezer or at the lower back of the unit..
Then brush them off or blow them off with a compressed air source. You can also try using a vacuum.
Have you checked the condenser fan? Is it starting to fail ?
Your symptoms indicate a failure to reject the heat from the condenser. But if the fridge has been enclosed for two years it may have worn the compressor out prematurely due to the excessive operating temperatures
Yes that would help your refrigerator get rid of the heat and run better. It will also save you money in electricity usage.