Prayers for your kitty.
We had a cat that went through something similar, at around ten years old.
Used a plastic feeding syringe to feed him, Hill’s MD diet food that vet recommended, and mixed with water.
We fed him that way for quite a while till graduated to eating off a spoon, eventually went back to eating normal.
He did end up getting two insulin shots a day, which he didn’t seem to mind, maybe because he got a treat :) after.
He lived another 7 happy years.
We also gave him some liquid vitamin B12 for a while, and always kept Karo syrup on hand, as we did go through a couple seizures it worked to bring him out of it.
Thankfully, we had a great vet with reasonable prices, at the time.
http://www.vetstreet.com/our-pet-experts/preventing-and-handling-diabetic-emergencies
I have some liquid b12. Wonder how much you give. I have read it can help. Maybe even a drop in her syringe would help.