It generally passes much faster than that (around 6-8 hours, maybe twice that with a high dose). If it seems to be getting less intense than it was before, I would simply wait it out, and only approach the drug in the future with great caution and in lower doses.
I would guess that you have a very low benzo tolerance, and an abnormally slow metabolism (or you're taking cimetadine or other enzyme inhibitors, which are causing you to metabolize it slowly). You took a very large dose for a benzo-naive individual, which is contributing to the long duration.