The sentence is “今日は中止なの?!じゃなきゃ家を出なかったのに”
From just reading it on my own I am guessing it’s meant to mean along the lines of “It’s cancelled today? I wouldn’t have left the house if I knew!” However what I am not understanding is how this actually breaks down to mean this structurally. It seems entirely backwards.
じゃなきゃ should mean じゃなければ, if it is not that case/that way
家を出なかった , I wouldn’t have left the house
のに, Even though, or just emphasis I guess
“It’s cancelled? If it is not that case then I wouldn’t have left the house.”
How exactly does that make sense, shouldn’t it be flipped entirely? If it IS that case then I wouldn’t have left the house would make sense. So why is it using a negation here saying if it wasn’t the case? I must just be missing something simple but I wasn’t sure where else to ask, any help is appreciated.