I think this is something that people don't appreciate about being acclimated to sugar coffee. It takes a while to adapt, you can't just try it periodically and try to convince yourself it's better than the milky alternative, contrast is too significant, like comparing a pear and a slice of dry whole grain bread, or walking vs driving, or going to the gym vs not. A couple of months though and you'll probably be well on the way. In a pinch I'll grab a black coffee from McDonalds, since it's more on the medium side anyway, and it's perfectly serviceable.