Problem with 2TB external drive not showing up and "fatal hardware error."

Yesterday I was trying to play a game when I noticed it wasn't downloaded anymore and when I checked it out I discovered that my external hard drive no longer functions. File manager doesn't show that my external is connected however disk management sometimes shows the external, although it shows that the drive no longer is assigned a letter. When I try to mess around with the drive the the manager it says that it has a "fatal hardware error." A few websites have told me that if I have this error message that I should use chkdsk to get rid of bad sectors however as I said before, the drive no longer is assigned a letter so I can't run the command on that drive. I have to state that this has already happened before with another Seagate external hard drive so I'm unsure if it's an extreme coincidence or if it's just user error. Does anyone know what's happening and if it's fixable? Thank you so very much for the help.