What are the symptoms when you try to use the drive? It's possible (but not that likely) that you just damaged the power supply or connectors and the drive itself is still fine. But most likely, it's toast.
If the drop actually did something -inside- the drive itself, which it sounds like it did, there is a very good chance it is gone forever, or you are looking at sending it off to a company with a clean room so they can open it and recover data...if its the latter of the two, it is going to be expensive, search for hard drive recovery service and see what ya can find.