About a week ago, I dropped it.
From a non-technical point of view, I think that sums it up. You need to get it repaired, I feel. Computers do the most weird things - it's not always "Garbage in/garbage out". I had a Maxtor hard disk that was "Failing", according to their checking software, for ages, but I didn't know till I did a spot check and thankfully discovered it before it crashed completely and lost my data.
If you can afford it, I would think about buying a replacement one anyway, if only as viable disk while it's being repaired. At least you'll have a spare, and you could keep it as such.
We work our computers harder & harder, and they get hotter & hotter. I've had my share of HDD troubles lately, possibly through overheating, and an extra one to fall back on is no luxury.
Just a thought... ;)
Bean.