You are a lefty, so it might not work with your explanations, even if they are right when one knows the left handed fact.
In fact, you have to first release the tension of the strings by lowering them at least a whole tone.
Then you have to screw the truss rod with whatever gets in the holes (this was meant to be used with the buckle of a belt), so turn clockwise as we say. It's an American made bass, so it doesn't have a typical British anti-clockwise thread. 😉
Proceed by 1/4 turn and retune, check and start again until you have the neck relief you want.
If it's going the opposite way, go the opposite way too, so unscrew.