I know someone who was on diazepam for only a year and he says that it took him longer than a year from the point of final dose to start feeling himself again. I know diazepam is not the same class of drugs, but hopefully the same is true for you - the longer you go from the final dose the more yourself you feel.
Well for one, you’re not supposed to take benzodiazepines longer than a few weeks. Benzo withdrawal can be life-threatening if you’re accustomed to a high enough dose.