How come the music on my iPod is gone?

Q: I have the little ipod shuffle that was full of songs from my itunes library until the other day when I went to recharge my ipod. When I put it on the ipod dock & plugged in to the USB port, a message came up that said my ipod is synced to a different music library, then gave me options. I DO have a different cpu tower & had to put all my music cd’s into itunes again but that was months ago. I think I’ve charged my ipod since then but am not sure.

I probably clicked on the wrong option that said “transfer….(something or other)….I thought it was going to transfer music from “THIS” library ( my newly created one) to my ipod. Today I went to recharge my ipod & it said “Ipod sync completed. Eject ipod” BUT THERE’s NO MUSIC ON MY IPOD !!! I’ve went into the settings and contents & the contents is a blank page-nothing on ipod! What did I do? I transferred everything OUT of my ipod?? To where?

All I want to do is put my ipod on the dock, plug into the usb port & have the 240 songs I have checked (that’s all the shuffle holds) to be synced to my ipod. It says it’s already done then I take it off & there’s nothing on my ipod!