Missing music from iPhone after synch

A few weeks ago I plugged my iPhone 12 up to Mac computer as I do all the time to drag songs over to listen to on my phone, this time it erased any song that I didn't pay for through iTunes. So half my music is gone off my phone now, basically anything from a CD, or a file given to me, or downloaded from any site that is not iTunes. It's like Apple will not let me play anything anymore that I didn't buy from their site? I tried calling Apple and also looking online for a work around. The song displays on my phone in the color grey and says "This Song is not available in the country or region. I am in the U.S. also. I have never had this problem before 3 weeks ago. Is this just some new update that I am not aware of? No more music files on your phone that are not purchased? Anyone having this problem and I am just out of luck and should ditch apple?