Hi stuckboss,
I have experienced a similar problem as Cesarion. I have no idea what caused it. I had Apple Music and iCloud Music Library turned on. On Monday night I was listening to music on my AppleTV. I added Rihanna's Sledgehammer and Fall Out Boy's Ghostbusters to My Music. On Tuesday I listened to a TWiT podcast on my iPhone 6. Then I went to listen to these 2 songs and I found a completely empty Music Library. I was very confused. I decided to listen to an audiobook in iBooks and found that it too was completely empty.
My phone had several gigs of music downloaded from my iCloud Music Library. There were some songs from Apple Music. However, there were very few songs I add to my iPhone from Apple Music. I usually just stream Apple Music.
When I got back home and reconnected to WiFi I turned off and then on the iCloud Music Library setting. When prompted to Merge or Replace I selected to Replace the library on my iPhone. I went back over to Music and it stated "Loading Library". Just like Cesarion it stopped with an error message that it was not possible to load my iCloud Library. I repeated this process several times with the same outcome everytime. I power cycled the iPhone and encountered the same outcome. I connected the iPhone to a power source and encountered the same outcome.
How do I reset the music library on the iPhone? I want my music back.
Thank you,
Charles