my itunes library is completely gone

Start here http://support.apple.com/kb/TS2715?viewlocale=en_US&locale=en_US and check the posts listed on the right hand side under More Like This.

Empty/corrupt library after upgrade/crash

Hopefully it's not been too long since you last upgraded iTunes, in fact if you get an empty/incomplete library immediately after upgrading then with the following steps you shouldn't lose a thing or need to do any further housekeeping. In the Previous iTunes Libraries folder should be a number of dated iTunes Library files. Take the most recent of these and copy it into the iTunes folder. Rename iTunes Library.itl as iTunes Library (Corrupt).itl and then rename the restored file as iTunes Library.itl. Start iTunes. Should all be good, bar any recent additions to or deletions from your library.

See iTunes Folder Watch for a tool to catch up with any changes since the backup file was created.

When you get it all working make a backup!

tt2

thanks that helped me! its a pain plugging in your phone and all the music just disappearing

This was very easy to perform with immediate results. Thanks!

You're welcome. 🙂

tt2

This worked perfectly... thank you!!

You're welcome. 🙂

For anyone else with similar symptoms there is now an updated version of the earlier advice at:

Empty/corrupt iTunes library after upgrade/crash.

tt2