I am afraid that you can't fix this if you accidentally dropped your drive onto the ground. By now you hard drive should have bad sectors because of the shock it received and the extensive powering and use will compromise it forever. If there are no alterations on your hard drive regarding scratches, missing parts, etc. you can send it to a warranty service for a replacement but I doubt that you will receive a new one. This could easily be noted as a lost cause because your drive will never be usable again. I suggest that you should use a Simple Tech solution to erase the drive and fill it with zeros on the entire surface which in this case means data loss for all the content it was on the drive before the error. Try again and connect it to your computer and if it fails again, use my advice regarding a warranty service.