You could try plugging it directly into a SATA port on the motherboard. If you are lucky, and the USB board is the part that broke when you dropped it, then it may work fine on the SATA port. Failing that, you will probably have to spend some money. Maybe buy an identical external drive, open that one too, and swap the hard drives. Or you could try a disk dock - they aren't expensive, and they can be useful.
I would suggest copying the data off the drive, then consider discarding it - the drive may have been damaged when you dropped it, and it would be unfortunate to put more on it, only to have it fail.