Help! mangled my entire music library

Few days ago, i noticed when i plugged my mixer in it woudlnt turn on, and my itunes folder has been reset to my C drive. Using a mac. Dont know how, but somehow it got switched. Over the summer i moved my entire music library from C drive to external USB, my itunes folder location was set to external drive. But now it was back to C drive. I have two copies of all my music on external now, and probably another copy of all files on C drive...total shitstorm. But now NONE of the songs in my itunes playlists work, cant find original file. I consolidated libraries, have two xls files in both external and C drive now, but playlists still dont work!!! HELP! spent all summer organizing songs into genre playlists

when i do a quick look on the music file that itunes cant find, says location is file://localhost/my external HD name. this is even after i save my itunes folder as that current folder.

I noticed in my main itunes screen, there are duplicates of all the songs with exclamation (not found) files, located right where i want them to be, but this is not the file i have in my playlist....so-how can i update myplaylists to find my proper location of the song..without switching everysong manually..

Are these in the Traktor collection? If so select all the songs in the playlist and do a check consistency. It should show you missing files and give you the option to find missing.