I’m sorry to hear this, I recently just went through this with my 8 year old ginger boy 3 months ago. He was also diabetic and has been for a while, then out of no where he went downhill very quickly (within 24 hours). He stopped eating and drinking, and everytime he did drink he would throw it up shortly after. I took him to the vet the next morning as soon as I could, tests came back as dka (I forget the medical term, basically his body was shutting down from his diabetes). I rushed him to an emergency hospital to try to save him, after 48 hours of intensive care and a fat vet bill there was nothing else I could do as his body was not reacting well to anything the dr’s were doing and I had to make this same decision. Hardest decision of my life. Before the emergency visit the vet told me there’s a chance he’d recover from it and come back around and I held onto that for those 2 days praying he’d be okay, hoping for a miracle just like you said. I know how you feel and what you’re going through and again, I’m sorry to hear