I feel for you since I fell into the exact same trap. I just went into automatic and remapped as much as I could to match my usual playing style only to find out that the UI doesn't update the mapped keys.
Took me ages to work out how to drop something since I didn't know what key I'd remapped the default "R" to. It's the same as your sheath/unsheath weapon key, by the way.
It would be nice if the UI wasn't absolute crap on PC. *sigh* Oh well, we're all having fun hitting every button to see which button does what.