Does it have the same meaning of "breathing down my neck"? If not, could you please post the meaning? :)
It must be the same, although the notion of "my back" means it's also not in front of me or to the side, so perhaps the speaker feels even more claustrophobic and creepy than the other expression would signify.
Well, if you're sitting at a computer and someone is standing behind you....
"Breathing down my back" gets about 303,000 hits on google, while "breathing down my neck" gets about 1,750,000. From the context, the back version is clearly just a less common variation of the neck version.
Both mean someone or something is uncomfortably close, usually in a metaphorical way but sometimes literally.
Maybe, it means that you are shocked, where your sweat flows down your back