External hard drive not showing up in Windows Explorer

Hi,
I have a Seagate 1TB external hard drive that stopped responding; it is NOT brand new, it's full of very important data and it's really freaking me out :/
I have no idea if this has anything to do with it (well, actually, I'm afraid it's the reason for the problem), but a little bit before it stopped working I lifted my laptop and it slid off the table - but it didn't hit the ground, the USB cable for it is very short, so it just dangled for half a second until I lifted it. This has happened before, and caused no problems - I am aware it's reckless, but carrying my laptop around everywhere has consequences. Fast forward 15 minutes later, I wanted to open a file on it, opened the drive, and when I wanted to open a folder inside of it, explorer froze. After trying to kill the process in the task manager (and failing), I figured the easiest thing to do was to disconnect it manually, like I do with my flash drives occasionally when this sort of thing happens.
Then I stopped responding - well, when I plug it in, it makes this beeping (?) noise for a couple of seconds, and my computer makes the "new device plugged in" sound. After maybe 20 seconds of silence, the computer makes the "device disconnected" sound and the light on the hard drive starts blinking (it has been continuous up until then). I tried plugging it into my other laptop, and it did the same thing - the beeping, connect/disconnect sound - except the other laptop showed the process of "installing the driver for the new device" (its system is freshly reinstalled yesterday, I had no chance to connect this external hard drive before that moment). Can someone please point me to the possible solution of the problem? Thanks in advance and sorry if the English isn't completely understandable, it's not my mother tongue.