I know how you are feeling, I have this problem too. My research said it’s called an ‘ear worm’, I know the name is disconcerting but honestly it’s nothing to do with worms in the ears lol. I started noticing this problem a few years ago and couldn’t understand why I hear a song all the time and often it’s not a song I like, you don’t get to choose and it makes this even worse. There’s quite a bit of info about it online and can be helpful. I sometimes pick up a tune from a television commercial, they have some catchy tunes today to sell stuff. I don’t have a cure for this to share with you, I did read that it’s caused by depression and anxiety, it makes sense for me but perhaps you might have other reasons for having this. I would suggest reading about it and see if the helpful tips might work for you, good luck.