GE fridge - won't cool; freezer and lights and fans work?

My GE fridge (21.6 cubic ft., Frost-Free model #TBX22RKB) stopped running. The light is on and the freezer works. I flipped the circuit breaker off and on and it started working again, but only for a couple of hours before the problem repeated. Is it the compressor, a relay switch, or something else? (If this seems an intelligent question, don't be fooled: I'm an idiot! If there's not a "simple fix" please tell me so I can call a professional!)