Back Against the Wall

[keannu]

Source : https://www.idiomsandslang.com/have-...inst-the-wall/
(Have One’s) Back Against the WallDefinition: Have few choices, be cornered
Example: I’m really sorry I had to lay Jason off, but my back was against the wall—if I didn’t, the company would have shut down our whole division
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1.This seems to mean that one is cornered in hot water. Do you use this a lot?
2. The underlined "if I didn't" is used wrong, to indicate a counterfactual conditional, it should be "If I hadn't", right?

[Tarheel]

1. One, you mixed up your expressions. Two, I don't think I have used it, but I understand it.
2. That's right.