There are other ways to find your music than through Limewire.

Try searching for it eg. search for mp3 or whatever format your downloads are. More on this in this guide. Also try going to the default save location and see if Limewire just lost connection to the downloads.

Making an Audio CD using Nero 7 (Nero Express) - Link

To get your downloads back to your Limewire Library look here:

Click here for info and screenshots - Link
note: In your library your filesnames should have black font if they are shared. If the font is red you are not sharing the file. You can correct this by right-clicking on the file(s) and choosing "Share this file"