I hate to give out too much info online, for fear someone will skip the vet and follow internet advice...but typically, if it's "JUST" HGE, metronidazole will be administered, as well as sub-q or IV fluids at the E-vet. Sometimes Cerenia will be prescribed for vomiting. None of these are things "regular" people have on hand. The metronidazole is critical for preventing secondary infections that can cause a dog to become septic, and the fluids are obviously necessary. Cerenia is a powerful anti-nausea medicine, often used in parvo puppies.
The thing that bothers me about an HGE diagnosis is that this started a couple days ago, and HGE usually is more sudden. This sounds like it could be something bigger getting way out of hand, especially since she's already ON an anti-diarrheal, the Canikur. Could this be an obstruction? Pancreatitis? Was bloodwork done when you brought her in 2 days ago, and if so, what were the results?
Praying she pulls through and you get help NOW.