I'd see what your options are as far as retaking the test. If they say you can...
... then, as stupid as it sounds, I'd study for it. Believe it or not, it is possible to do better on the hearing tests when you know what to expect & what to listen for. Sit perfectly still, close your eyes, focus on what you're hearing, and as SOON as you hear the beep-beep (even if it's as much a faint click-click as a beep-beep), hit the button (if that's the setup they're using). Don't wait until you hear it "loud & clear" -- if you hear it, you hear it and that's enough. Ideally, find an AME or a hearing specialist in your area who uses the same sort of setup, and see if you can get a hearing test from him. If his setup confirms the same loss (preferably ask him to run at least your right ear twice), then you have the waiver route. But, if getting used to the test & what you're supposed to hear will help you get a little less loss, then it's definitely be worth your time to get retested.
Do some research at the ROTC unit, and find out if there will be another physical that definitively determines your pilot/nav qualification, or if that was the one. Then ask about retests, waivers, etc.
Hopefully somebody here closer to the ROTC process can give you some good words of advice, but at the end of the day, you're the one who's going to have to make it happen.
Best wishes!
Snoopy