Who told you to do that? Because ironically phenibut has similar tolerance issues to benzos and real nasty withdrawal although it is probably less addictive.
Have used it many times over the years, a MUCH better alternative to benzos for anxiety, because it does a similar job without effecting your mental state, judgement or turning you into a total zombie which can happen on benzos; being a nootropic phenibut can actually improve your mental state. You just need to watch the dose, I would say 500mg's max daily and once you are off klonopin take it down to 500mg's once every two days, then if you plan to use it in the future more regularly you need to cycle on and off it.
Have read a few times some people thinking phenibut is perfectly safe with no sides, taking up to 2-3grams a day and boy did they get a surprise when trying to come off it, its a real ugly thing; I have had bad sides from taking around 800mg's-1g daily for a few weeks.