Is this normal for Texas???

My gas bill for Dec 30 to Jan 30 is $521- I'm new to Texas and I'm completely horrified. Is this normal?? In the northeast, our winters last almost the entire year and I've never paid this high for gas in my life. Someone, please help me understand this. I've called CenterPoint and they keep giving me run around bullshit. I'm so frustrated to the point of tears. I also have to add that I literally do not run the heat all day long. I'm never home and when I am home, the heat is on auto at 72 the most. My stove is electric and I don't run hot water all day.... It's not adding up. I'm so confused ???

Edit: The home is 3000 sqft . (No dryer, stove is electric, gas water heater, no generator, no pool) I only heat one floor when I'm home. When I'm not home the heat is completely off.

My bill breakdown is this exactly:

Customer charge: $19.50
Storage inventory charge: 1.70

Base amount: 86.12
Gas cost adjustment: 373.99 (What does this even mean???)

I'm assuming the extra $40 is my service initiation fee.