14 yr old lab throwing up?

My family black lab is soon to be 15 in July. Two days ago my dog started this weird coughing thing. It was pretty close to the sound of a dog trying to vomit. Actually that could have been what it was. The next day it got to the point where she would do that nouse and she would actually vomit up her meals (she only ate twice a day). Now she won't eat and she stopped the coughing and vomiting (that's concerning because she LOVES food). Also today she just started breathing weird. Like, she'll exhale heavily. We're taking her to the vet tomorrow but I just want some sort of idea what's going on. You know, prepare myself if it's time to say goodbye :(