I have a similar problem with black coffee, but in my case it’s just when its hot, so I’ve learned to enjoy it cold and that helps in regards to the coffee destroying my stomach. I’m not sure what to add to your coffee that would make it bearable and not break your fast though.
I recommend brewing coffee with cold brew method. I brew mine in the fridge and if I want it hot just heat it up. Cold brew is less acidic
“Cold brew coffee is less acidic than hot brew coffee and is a better choice for people with acid reflux and gastrointestinal problems. The lack of non-deprotonated acid molecules makes cold brew coffee a smoother drink for most people.”Jun 7, 2021https://theoldcoffeepot.com ›