I can't understand why anybody should have a problem with earworms (from the German "Ohrwurm").

First, make sure the last song you hear before you go to bed is something you like--I tend to put on Baroque music--very soothing.

Second, watch no commercial TV.

Third, in general, if you listen to music at home, you should be able to ensure that the music you hear is what you want to hear (obviously having kids in the house may complicate this).    Don't listen to currrent top 40 at all.

My head is stuffed with classical music, country music, Beatles etc. I wake up every day with a different song in my head--but it's these, or a song I'm trying to learn.

No danger of Neil Diamond, Barry Manilow or current top 40, etc. getting in.

This seems to be a classic tempest in a teapot.