Wow Sadie,
That's not a laughing matter, I really hope you are okay. My grandmother missed the last step on a set of stairs leading to my brothers basement.
She didn't brake her ankle but crashed her knee and face on the cement; she's okay but it was very scary.
I am glad you didn't fall but caught yourself from taking a flight of stairs; that could've been deadly.
Mike
p.s
Please be safe during the new year....