I'm pretty sure you can flash a factory image in Odin to revert back (I don't have the specific info on how to do that), but that would require a FULL data wipe of your device.
EDIT: OK, here's what I was quickly able to find. The procedure isn't very difficult, but if most of this seems to be above your head, it's probably best to just leave it alone! As usual, I'm providing this info only FYI -- do NOT blame me for anything that happens to your device. You could, in theory use this as an opportunity to root your device if you so desire (since you have to wipe it out and start over anyway), but otherwise...
REMOVE YOUR SD CARD IF YOU DON'T WANT IT WIPED!
See here:
[GUIDE][VZW Edition]How to root your Galaxy SIII & More!(ROMs/CWM/Stock) - xda-developers
Now, you're not interested in rooting, so skip down to "Section 5" of the first post. Follow the instructions there to flash the factory image and restore your device to the older software version.
Notice, there is no image for the last official OS, VRMBM1, which is what you probably want. (VRMBM1 was the last version before this recent OTA). Still though, this will get you back to point where you can start fresh...