Burning songs to a CD should have no effect on what is stored on your hard drive. Unless you had a hard disk crash, or inadvertently erased your music through the main menu, the music should still be there.
If you recorded your songs to a CD-RW there's a good chance that a CD player will not play it. I burn all mine to a CD-R.
The owner's manual cautions against using CD stablizers, or printable CDs, as they may damage the CD mechanism.
That's all I can offer. Sorry, and I hope you get everything worked out.