So, I have had this affliction my entire life, too !

I had no idea there was a name for it. Some days it's all day long, and other days I am spared completely. And sometimes a week will go by and I have that few lines of the given song on a feedback loop to where it IS maddening.

Now I am going to need to investigate this more along with the neurotransmitter connection because that has also been something I've wondered about.

At first it seemed like kratom helped with my underlying imbalance and then, of course, as everyone here knows.....it exacerbated it and made it a hundred times worse.

I am sorry I have no solution, OP.....I have never fought this. At times I just run with it and break into song (and since it's usually an oldie everyone knows) others may join me.

I suggest continuing with the meditation daily. Try and allow yourself the freedom to experience whatever happens and don't "push against it" by developing frustration (I know it's tough). But I bet that it will eventually help...