Lately I've been having the USSR national anthem on repeat in my head.
Are you not able to stop thinking about it?
No it is constantly playing in my brain
That happens to me sometimes too. You should try thinking of another song in order to get the current one out of your head.
I can't think of anything else.
There's plenty of songs out there, I'm sure you could find something. Just search online and try to find something. It will probably get annoying if you keep having this in your head.