Help ! iTunes not finding iTunes media

[From A Buick 8]

HELP!!! . I was moving songs to a playlist and iTunes quit responding, so i had to force quit. When i did and restarted iTunes it could not find my iTunes media (i keep it on an Ext Drive). So i restarted but still could not find it. I can open the Ext drive and navigate to the Ext drive, even use VLC to play files from there.

Any ideas.

 

[From A Buick 8]

So i held down the option key as i opened iTunes and i picked one of the previous iTunes files ( think that is what it is called) that were on the ext hd. The one i picked which was the most current after the one from today ( because the one from today was not working) it seemed to open up. But i have added alot of Tv shows and movies since march, so what should i do to get iTunes to find those and add them.