try to shut off about one or two days. wait for frige ice completey melt and make it clean. then tune it on again. i think your frige cold air blockd from somewhere. if it still not working then you need someone's help to fix it.
It is not good to put freezer in the garage. There is lubricating oil in the compressor. In low temperature the oil become like peanut butter. This put more load on motor when it starts. It may burn a fuse.