Jenny if you pull the freezer out again yo will see a, probably, plastic tube that runs down from the condensation drain in the freezer to the heated tray ate bottom. This will probably be blocked. It will have little clips or grips that hold it in place. Remove the little tube and put it in a bowl of warm soapy water and give it a soak for a few minutes or until you have cleared the blockage. Warning it is not a pretty sight and will probably look like grey and brown slime.