Me too. Usually changing the script slightly to exaggerate or be bombastic works for me. Ex. “How are you today?” “I’m doing just fantastic so far, how are you?” Or “ch-ch-ch-chillin,” sung to the tune of the Chia Pet jingle. Usually gets me further than “Good, you?” Social interaction is just another game I’ve had to get good at.
I hum to myself nearly constantly. If it’s not the song stuck in my head, I’ll just make up a tune. I quite like it, really.