How do you get to a file that is unaccessible?

Hi, really sorry but i have tons of pictures and that for some reason i can no longer access anymore~~! It’s on my external harddrive and when i click on it, it says “F: Pictures not accessible. The file or directory is corrupted and unreadable.” Does that mean that those files are forever lost to me??? Please help me~! There are pics that I am not able to recover…TT_TT
Thank you.