Will my dog die? :(.. She's not eating anymore.?

She's 4 years and a mixed dog.. She's almost like a chihuahua but a little larger.. At her 4 years, my aunt took her to mate with this dog... And after 3x of mating.. She's still okay but after 1 week.. She began feeling really ill and barely eats.. Then we took her to the veterinary(cheap veterinary because it's the only one near).. The veterinarian said it's because she might be pregnant and she gave us just vitamins.. Then after a few days, it's getting worse and doesn't eat at all but we feed her forcefully with milk and vitamins.. All she does is sleep and gawks.. Gaze.. She barely moves now and really weak.. What can we do? Will my dog gonna die? :(