I will add that all of my music came back because I had all my music matched using iTunes Match which syncs everything in your library to icloud. I also subscribe to Apple Music. iTunes Match costs $24 a year but it may be worth the expense in case your library is lost or damaged even with songs that iTunes doesn't carry on Apple Music.
I saved my current library and renamed it to library.old and allowed the previously downloaded iTunes version to create a new library. Once it installs the previous version 12.10.11 check the iCloud Music library box shown in the embedded image below. Once that is checked on, all of my music in the cloud came back as it was before.
As a note, my library is extensive with 22,000 songs accumulated over the last 20 years and added along the way. Literally everything I had before with playlists, albums and songs was returned to the same state it was in.
I did use this article as a guide to make sure I renamed the library correctly. It may be helpful for you as well.
https://windowsreport.com/itunes-library-itl-cannot-be-read/
As with anything, things can go wrong so make sure you take every step you can to backup files and make sure to note where your music library is saved in your system if it is not the default iTunes creates.
As a progress note from earlier this week, my iTunes is as stable as a rock and allows me to add, delete and update my library with new music with no freezes or crashes. My music is a major part of my life and it was a huge relief to be able to bring it back to the way it was and enjoy it again.
Good Luck!