I was once working with the national oil company on the LPG Reticulation Project. The case in 1995 in Wangsa Maju still in my mind. But that was an LPG gas cylinder (also not ours), and the problem was also not the gas cylinder. The house owner heat up a pot of leftover kuah overnight. It was the cast iron type stove ... and the flame died, so the whole kitchen was full of gas. Next morning, his sister in law went to the kitchen and switch on the light ....
What can I say ? ... always be careful. LPG (mixture of Propane and Butane) is heavier than air thus it will collect at the floor. This is more dangerous than Methane (or known the Natural Gas). Methane is lighter than air thus it will floats up ... and its LEL and UEL band is also smaller (slightly technical here), difficult to ignite.
Having a fire extingusher is a very good idea. All homes should have one.
Anyway! Hope your get well soon.