@SugarGracie THANK GOODNESS
@Chris & China (GA) and
@Rebecca & Max (GA) were here!! I am hoping you and your kitty have started to calm down from such a frightful night!
I want to repeat what Chris/Becky said and confirm you understand - NO insulin tonight.
IF she was ever diabetic (your vet may have totally misread the fructosamine test results. Up to 350 on Fructosamine test is within normal range for a NON diabetic cat. Fructosamine tests are not read the same way that pricking her ear blood glucose tests are read/interpreted).
So, IF she was ever diabetic, my money is on the food change being enough to bring her down to normal numbers and control her diabetes. Usually a food change is done most safely before adding in any insulin, and may take to to a month maybe for you to see good results on its own. Many cats have avoided insulin altogether with a simple food change.
You can monitor her BG today some once you get the ReliOn strips - she will likely be pretty high, even tonight she may be high, but do not worry about that. It takes awhile for the glycogen she released last night to stop the plummet to leave the system.
Hopefully you can get some tests today/tonight and write them on your spreadsheet, so we can start seeing a pattern for how she looks without any insulin at all and after a hypo (remember she will be high today and perhaps into the night). It will be useful for you to indicate on your spreadsheet also when she gets fed (so we can see what food does to her BG). Decisions about whether to give future injections or not will need to be made based on this data (and input from the forum is best), you definitely shouldn't be doing any 1U at night any more. And the data will show us whether she needs any insulin at all period.
Does this all make sense and sound good to you? Questions?