12 units is useful for back up but keeping this is not a back up as you are last so you will be just wasting your time as it most likely won't be counted in your best 10 units. So drop it.
100%, I dropped society & culture a couple of weeks ago (I was coming third though and it was my best ranking subject) but I really wasn't motivated to keep doing it and I needed to free up time that I otherwise would have spent doing the PIP.