Eight puppies is a good sized litter, especially for a small breed like a Yorkie, and the pups may be taking a lot out of her.Some dogs develop hypocalcemia (low blood calcium) due to the demands ofproducing milk for a large litter of puppies. These dogs will have panting, restlessness, drooling, vomiting, tremors, weakness, may have a change in personality due to the effects of low blood calcium on the brain as well as stiffness in their gait. It can progress to seizures and if not treated, death.If this is what is going on with her this is a true medical emergency and she needs to be seen by a veterinarian immediately. They will check her blood calcium levels and start intravenous calcium immediately. If this is her diagnosis the puppies will need to be bottle fed and weaned now, she cannot feed them any more or she will become hypocalcemic again.
Other possibilities are an infection, either mastitis or a post-whelping uterine infection.
Does she have any green or yellow or foul smelling vaginal discharge?
If you look at her mammary chain are there any areas that look very red and feel hot and firm/painful to the touch?
Treatment of an infection can be antibiotics but as sick as she is she may need to be on intravenous fluids and injectable antibiotics and in many cases the pups willneed to be weaned.
Whatever is going on with your girl she is very sick, and these are not conditions thatcan be treated at home, she needs emergency veterinary care. Whatever you triedto give her orally she would likely vomit back up, further dehydrating her.
Best of luck with your girl, please let me know if you have any further questions.