My entire library of songs suddenly disappeared... any ideas?

Go to your LW library, click on Saved Files & now click Explore.
Are they there??

If not then outside LW, do a search for one of the song titles.
Is there any chance that you (or someone else) might have deleted them by mistake?

They're not in the folder, and I did a search.. nothing came up. I also checked the recycling bin, nothing is there. I really don't think I could've deleted them, and no one else has access to my computer.

I had everything in a playlist, and paused it for a second. Then later when I opened the window back up and tried to play a song, it said the file was missing. And then I realized my library was empty.

Strange.

Whatever is deleted from the LW library won't go to the recycle bin. You would need a file recovery program to retrieve it.

It sounds a bit weird. Don't want to go jumping on the old bandwagon but...is your LW an official version from www.limewire.com and have you run an antivirus scan lately??