My I tunes library deleted!

Years ago I put together. 64gb I tunes library from my own resources paid for so legally mine Now I am being told that when I purchased a new I phone and subscribed to Apple Music I donated these tracks to I tunes -I most certainly did not and following that Apple deleted them all without any notice when I did not pay for a subscription to Apple Music. This is theft and I want my previously bought and paid for files back NOW. How can they get away with this. I am elderly and disabled now and have not kept up with technology and if this is what is being allowed to happen then it is being allowed to commit theft.

[Re-Titled by Moderator]