OK! Don't panic!
As I know, the RAW hard drive often could be fixed by reformatting! So, you also give it a shot.
However, since you've saved something important on it, you are supposed to act carefully before you start to format this drive.
1). DO NOT save anything else on this drive before you've restored all your needed data. Your best bet is not to use it.
2). Connect it to your computer and try to restore your data back for free by applying some RAW drive data recovery freeware online. RAW drive could be caused by virus infection, hard drive damage and computer system problems, etc. Therefore, in order to get back your data, data recovery software could be a good shot.
3). DO NOT save your retrieved data on the same drive in case of data recovery failure.
4). DO NOT forget to format this drive after data recovery process.
5). Learn to make regular data backups from now on.