HDD External drive usb 2.0 not recognized

Hi,
I have an external drive which has been working fine until a few days ago. The drive used to load as H: port and HDD and I would click and all my data would be accessible. When I plug the Driver now it does go into the motion of appearing but is now E: and has no octets and I get the message in that the drive is not accessible and that the data is corrupted. I have downloaded easeus but it seems to be running for hours and no files are actually retrieved. Could you let me know if it is terminal or if I will be able to recover these files. I have some important information and would hate to have lost it all. Thank you in advance.