I've wondered the same thing. I always thought it meant dear untill I saw otherwise. But then usually you can tell.
I tend to stay away from these mostly.
Someone said to say dear is old fashion and out of step with time. Calling someone dear is about your heart not time. I don't usually speak this word but use it in letter writing and even now and then with my sweet little ones, such as saying, "dear one" or "dear child" especially at the end of a sentence or explanation. The word darling doesn't come out for me though.
Don't feel bad, I'm sure no one took it to mean anything but dear or darling husband.