ITunes library gone?!?!?

Alright so 2 days ago, verizon fios went down and i had no internet, tv, or phone. so during this outage, i decided to organize my folders on my computer (pictures, documents, music, etc.). after i had everything organized, the next day itunes couldn't recognize some of my music so I had to find the folder for each song. today my service came back on and i click on itunes and everything is gone, no music, no apps, nothing. It's as if i'm a new user. I still have all my music on my ipod. how can i put this all back onto my itunes?