To manage your anxiety perhaps you should look into other things as with benzos once you ratchet up your tolerance really high, trying to maintain that once you're at that point is going to be difficult and you will be faced with very difficult and dangerous withdrawals.
I wouldn't recommend starting a new substance just on your own, but, doing so with a doctors advise.
I just know the amount of klonopin you're taking probably isn't medically advised, as it's difficult to even get your hands on that much of it at once. And acquiring it from the street leads to the potential its a bad press and you can end up dead from this.
There may be a much better solution to the problem you're facing.
Sorry youre going through this, if youre unable to stop a severe relapse due to mental health it may be advisable to go inpatient and try to stabilize and get off the bender safely.
I would consider addressing the underlying problem which is the mania and try to stabilize that way rather than covering with benzos the byproduct symptoms of the mania which is the anxiety.