Kitchen Large Electric Appliances - GE Refrigerator cool but not cold.

I have a GE TBXPAYERBB fridge that is about 8 yrs old. Has always worked well until now. It is still cold enough in the freezer to make ice, but feels wet and ice cream is mush. Milk is not as cold as it should be. I pulled it away from the wall and found the usual dirt/lint over the coils underneath, but not too bad. I shop vac. pretty well and waited 1 day. No change. I removed the back wall in the freezer and found a thin coating of frost on the coils, but not much. I melted it off anyway, but not much change. It appears that freezer fan and fan underneath runs all or most of the time. Air coming from under front of fridge is warm. Only a slight amount of water in tray underneath. Can't seem to get the ice maker to refill with water since removing it with the back wall. Maybe air lock. Any suggestions on where to check next for cooling problems? I am fairly familiar with automotive A/C and basic electrical problems.