Hi Kim,
What was the matter with Lucy when you said you'd had a rough couple of weeks.?
She might be nauseated and that might be why she isn't eating. Was she not eating last week when you went to the vet? Is she lethargic?
Not giving any insulin to a diabetic cat can be risky especially if she had been ill as she could develop ketones. Can you go out and buy a bottle of Ketostix from the pharmacy today and test her urine for ketones? It is important to know if there are ketones in the picture if kitty won't eat and has been sick.. Anything above a trace of ketones needs vet attention. It can lead to a very serious illness called DKA.
I'm glad you are getting your meter tomorrow.
It is really important to try and get her to eat something. Anything at all, it doesn't matter if it is unsuitable for diabetics at this stage....just get her to eat. Try sprinkling Parmesan cheese on some food. Or tinned sardines or tuna. And fluids as well are iimportant.
If she is still not eating I think you should go back to the vet and ask for antinausea meds such as cerenia and/ or ondansetron. Cats won't eat if they are nauseated.
Also if not eating give a small dose of insulin .....If she has been having 1.5 units, then try giving her 0.5 units or 0.75 units.. not the full dose.
But don't let it go on, go to the vet and insist on anti nausea meds if he can't find the cause.