Oh, poor thing, how horrible and frightened she must be. She could have something stuck in her throat, she could have respiratory issue...who knows...but she can't go on like this. See if you can get her to drink something or eat cut up bits of grape or blueberry,,,something that might help clear her throat if it's just something stuck - watch to see if the situation subsides. If it's a respiratory ailment from an infection she may need meds. Keep her really comfortable and pleasantly warm.
Honestly, if it doesn't subside quickly you have an emergency on your hands that only a vet may be able to resolve in time. And here it is at night.....not good...unless not night where you are?. JJ