Erased Music App on iPhone... How can I get back library?

Trying to make space on my wife's iPhone X I "zapped" a couple of unused apps, and in the process inadvertently wiped the Music App. You can imagine how popular I was. I reinstalled it, and the playlists reappear, but there is no content in them. My wife spent hundreds of hours compiling her playlists, and this is a huge problem. For info, the music and playlists were loaded as part of the "family" access to Apple Music. I called Apple support and they said there was nothing I could do to recover the songs in their playlists, but would simply have to start all over again. The iPhone had not been backed up to iCloud since last December, but in any case I looked on iCloud and could find no way to even access the playlists and music from back then. Does anyone know how to recover the songs? Logically as I have not overwritten the iPhone with anything new they must still be there somewhere... HELP!!