Have a 500gb WD external notebook drive. All of a sudden it takes the computer about 10 mins to read it and when it does it tells me i have to format it before i can use it

Now i have scoured the net... THOROUGHLY... in the hope of fixing it, ive tried almost everthing.
DSKCHK wont work, says it fixes the bad sectors but upon scanning again it picks up same bad sectors.
Disk scanning tools, tried a variety of them, free and not free ( didnt pay obviously ) but to no avail, best one ive tried is Active Partition Recovery which picks up all bad sectors ect, recovers them, but same story. This program also also shows me the files on my drive.
Western Digitals own recovery program, scanned and says that there too many bad sectors to fix
Dwnloaded a file recovery program that shows me all the files i have on my hdd and allows me to back them up, so all files are still there. trouble is i dont have spare 500gbs to back it all up and buyin an extra hdd is not an option.
Disk has an assigned drive letter but the format type is being read as RAW opposed to FAT32 ( been meaning to change it NTSF before you say anything )
Now this wouldnt normally bother me, i`d format it and move on. only for theres is 6000 photos on it fromt he day we left to come to asia/austrailia and if i loose them the g/f will cut my balls off.
Is there ANYTHING you can suggest matey. I`m hopin you know something the net doesnt because chances are if its on the net, ive tried it.
P.S. atm its hooked up via SATA, same story