I have had an "ear worm" with same looping song in my head for 8 straight months. 24-7, 365. from moment i go to bed to moment i get up. what is this?

Not uncommon: amongst OCD sufferers and musicians. I've found the best way to combat repetitive brain songs is to expose myself to other catchy songs, often at higher volume. I once went to Disneyland (CA) and rode "It's a Small World." Mistake. I heard that song in my head for hours--at least until I listened to one of their bands, and then it went away. More serious cases require a visit to a shrink