I've never had a panic attack but a nocturnal one sounds awful, we're so vulnerable when we're asleep, I can understand how disturbing this would be.
Many members find they need to slow down towards the end of their taper so it might be a good idea to slow yours down but like you said, its doubtful the drug is offering much at this point.
It looks like what was there before benzo's will be there when you've recovered but it sounds like you've found a way to at least deal with them drug free even if you can't stop them.