I mean. Are you clean fasting? Dirty fasting? Personally, I’d say those calories and carbs are gonna cause a pretty negligible insulin/digestive response. Wouldn’t sweat it.
But yeah. Try and get the melatonin in cap/tab form.
I had a similar issue. All my supplements were gummies. But I couldn’t take them cos I had to take like 3 of each and there were a billion lol. Took me a while to swap them out for caps.