Poorly diabetic cat not eating

[daffydowndilys]

We have an old diabetic cat, she also has kidney failure.

She is being put to sleep tomorrow as she is so sick. Tonight she isn't eating at all.

She is on a high dose of insulin.

I'm presuming that I don't inject her if she hasn't eaten?

Poor thing. I really feel for her, she has gone downhill in the past 24 hours.

Can I give her sugar?

No. Definitely don't inject her. She would likely have a hypo.
So sorry you're having to go through this. It's the saddest and hardest part of having pets.