Lost music off iPod classic after turned mac off at the wall

I thought it was a myth that turning your computer off at your wall was bad! Turns out it's true!

I went to listen to my iPod today and it is saying no music! Strangely, my photos are still there, just not the music and videos.

I went through some forums and tried to follow some instructions on how to retrieve but i'm not very savy.

I went in to disk utility on my Mac and did notice that for my iPod it is saying that 84gb is being used which is how much gb roughly my music took up. Am I right in thinking this is a good sign and it is hiding in there somewhere?

I don't have all my files in my iTunes library and I don't think i've backed it up either.

Any help would be great as I feel like i've died a little inside