Retrieving audio files

Ok here it goes, I was tracking drums on 6 songs for an artist. I got my set up all going on song a. When I went to track song b I imported session data from song a drum tracks. When importing the audio files also went to song b. after editing the drum tracks on song b I selected unused audio files and accidentally hit delete instead of remove from session. I know, no backup and delete, bad combination. I saved the session on song b and reopened song a and the drums were gone. No files in the audio files folder......

I think they were deleted as unused tracks when I was cleaning up song b because they were imported with the session data and the source of those audio files were back to a.

Is it possible to delete files from another session when cleaning up another song?

And how can I retrieve, if possible the missing tracks? They are not in the audio files folder, I did the full data check. But they are greyed and italicized in the audio files bar on the right side of the edit window.

Please help

Thanks