Hi Jim,
The songs in my library are from apple music (not from local files), so they are not in the recycle bin (I checked it). I do have backup itunes library files called "iTunes Library.itl". I tried to open it (by following this instruction: Restore your library from a backup Back up and restore your iTunes library on your PC - Apple Support), the first few seconds i saw my songs that I deleted earlier but the songs are greyed out, once the iTunes starts to sync, those songs dissapeared). I tried to re-open it while I'm not connected to the internet, copy the greyed out songs to a new playlist but again, the songs dissapeared once I connected to the internet.