IPod Classic Error when connecting - I cant put new music!!

When i plug in my newish (6 month old) IPOD classic to the Mac it immediately tells me -

"Mac OS X cant repair the Disc "... ipod".

You can still open or copy files on the disc but you cant change or save files on the disc.

Back up the disc and reformat it as soon as you can.

Also this balloon comes up -

".... Ipod cannot be synced". You do not have the privelege to make changes."

This all happened suddenly.

everything was working fine until yesterday.

Sometimes I also need to force eject it to get it out.

And when i attempt to copy a song to my ipod it gives me

"Unknown Error - -61!!"

If i restore to factory settings do i lose all my music?

Or if i sync?

Thank you so much for hopefully answering me!!:))

Carlie