Why has my music from my library all been deleted?

Make sure your subscription is still active

view, change, or cancel your subscriptions

then follow these steps:

n your iPhone, iPad, or iPod touch:

1. 1. Go to Settings > Music, then tap iCloud Music Library to turn it off.
   2. Close Settings.
   3. Go to Settings > Music, then tap iCloud Music Library to turn it on.
   4. Turn on “Show Apple Music”

For other devices:

Turn on iCloud Music Library with Apple Music

https://support.apple.com/en-ca/HT204926