Most of my tones hang around for a week to a few months, but they eventually fade. Honestly, you (and me too) should be glad your tinnitus is from benzo withdrawal. Your system's overloaded with glutamate, which makes your auditory system hyperactive and causes all the weird tones, but glutamate also drives neuroplasticity. That means the stuff you're hearing now is way less likely to stick long-term.
You're still withdrawing, right? I think you'll just have to expect a bumpy ride until you're through the other side and then give it some time for things to settle to base line. Might even find it's downright liveable after all you've suffered!