How can I fix my iPod?

Today, I was listening to my iPod (120GB classic), and I clicked “next” to switch songs, but the screen froze. This happened several times, and each time, it froze 0:02 into the song, but the song kept playing. The first time, it unfroze after about 20 seconds. The second time, nothing happened, so I restarted it. However, when it restarted, I had no songs on my iPod. Everything was reverted back to factory settings. I’d just been listening to music a second earlier, then it was all gone!

I tried to plug it into my computer (Mac), but it says it’s corrupted. It showed up in iTunes for a second, asking me to restore, but then disappeared. I keep disconnecting and reconnecting, but nothing happens. (Unless you count my iPod getting frozen on the “connected” screen something)

There’s always a warning pop-up when I plug my iPod in that says, “The disk you inserted was not readable by this computer.”

Can anyone help me? I don’t want to sound melodramatic and say that I can’t live without my iPod, but I’m one of those people who seriously gets depressed when they don’t have music playing.