Music library

Now itunes has been discontinued, how do I manage my files? eg backing up and syncing iphone and ipad as well as music library - all on my macmini. All my music library is of my personal CD library (mostly classical) uploaded over the years. My personal playlists have disappeared. The albums do appear but I can't open them as a message comes up that a file for certain tracks can’t be found.

Where has my music gone? Apple has wrecked the great file management system which existed in itunes.

I can still access and listen to my playlists on my phone and ipad but am reluctant to update any OS on them in case I lose all access to my music.

Hope someone can help...

Vivian