Help save Neko from Diabetic Crisis

Hello, my name is Bonnie. My cat Neko is almost 7 years old; he's the light of my life. I know this is a huge ask, but my cat Neko is currently in the hospital. He has diabetes, and I did not know. I just had him at the vet last week; they didn't say anything was wrong. As of last night (May 18th), when he first got to the veterinary hospital, he's diabetic and is in ketoacidosis. He is really sick. I've been sobbing non-stop. If anyone can please help, I would forever be grateful. I just want him to be okay ☹️. Thank you to all who help, anyone who sees this, and to anyone who spreads the word. Your kindness is appreciated more than words can express.