TrueCrypt has an option 'Use backup header embedded in volume if available', which can be found under 'Mount Volume with options'. In case that doesn't help, it is very unlikely that the corrupt TrueCrypt container can be restored at all. There's nothing practical you could try. The way to recover your files is to restore a backup you have made earlier.
If you don't have one, your best bet is to try data recovery tools on the hard drive on which the container was initially stored. Large encrypted files make very lousy candidates for this to work, but if you're lucky, some of the data may yet be salvaged. As always, don't use the drive. Make a duplicate and take it out. Attempting to move the container back to the original hard disk has already greatly diminished your chance of success.