You might try running some data recovery tools like the ones suggested in this article. If the repair process begins straight away once again, I'd recommend that you leave it for a couple of hours to see if there's any progress and if not turn off the computer and connect the drive to a different one as a secondary storage HDD, so that you can try to get to your files to recover them. So you could try to restart and boot to safe mode, to see if you'd be able to. It's not really recommended that you interrupt this process, but really doesn't seem like you have any other choice since it's going nowhere.
