I have a stream of thoughts running through my mind every moment I am awake. Not sure that is the same as an internal monologue.

Luckily some part of my mind is able to step out of this stream from time to time and observe it as though from the outside. It is like sitting on the banks of river and watching the water go by. This gives me a sense of control and sanity.

Sometimes songs or melodies get into a feedback loop in my mind too. I wonder if we are experiencing something similar? Sorry that your thoughts are loud if that is disturbing. I guess I have had "loud" thoughts too. Best to you.