Just as a point of comparison, my gas bill, normally about $30 in the summer, was $440 this month.

That's the highest it has ever been, by about 50%. And it wasn't that cold.

It's your heat unfortunately. It's expensive. Fuck off commodities traders and Vladimir Putin is your answer. (People will defend the trading but the truth is that they panicked in the summer, prices went exponential, and then the energy suppliers had to buy and set rates at exorbitant prices because they are required to lock in before the season. This is different than heating oil which is set constantly by market, but supply is lower than usual because of a couple of refinery problems plus again, Putin - that's why heating oil and diesel fuel at the pump have not come down with gas prices ).