Created new library and lost my content

I have been trying to increase the songs that are available when I use Windows Movie Maker and in so doing I tried to convert a song to "acc" which had no impact. I then tried to create a new library and followed the instructions for doing that. Since then I have not been able to access my original itunes library, all my playlists are gone, etc. When I open itunes I have to select the library, which I do, and regardless of which of the two libraries I choose all is lost, except now I can only access stuff from the cloud but I can't undo that. It's a mess and I don't know what to do. Is there anyone out there who can help me?