What to do with a High gas bill?

My gas bill just came over 230 dollars from December 17th to January 18th. I was gone out of my house for 14 days. I always left the heater at 68 degrees. I also leave the heat on at 70 everyday. I'm in Atlanta and my appliance that uses heat are Water Heater, Gas Stove and Heating unit. Nothing else. And I don't cook. I've tried everything to reduce the bill. I even had apartment complex check for gas leaks, nothing found. Now the kicker. My place is only 650 sq Foot!!!! The bill is ridiculous and it has only been going up and up lately. What are some of my options?