Lost most of my music

Much of my music was downloaded from CDs many years ago. They have always worked with whatever phone or system I had. I no longer have the computer with the downloads. My new computer and iPad only show music bought in iTunes, not my original music. Now with iPhone 16 pro and new IOS26, it shows my library but most songs say “Not available in your country or region”. How can that be? I hate losing all of my music and can’t afford to buy it all again.

Can my music be recovered?