accidentally deleted lots of albums, how to recover

i have just deleted all my albums up to the letter R. This is not the actual MP3 files, but all the time I have spent getting albums to show as single icon etc. I have made lots of changes in the last few days. The newest file in "Previous iTunes Libraries" shows 5 days ago. Have I really lost all this work or can I recover it or do I need to rediscover all my music files from hard drive.

Can anyone help please.