Me too Treecie .... I myself had nothing to add to the suggestions silent meowlook contributed here,sound advice from someone who has much experience with this.... unfortunately many of us do so it really hits home ,we are here to give you supportI am so glad she is doing better.
My best friend ,my special love of nearly 2decades was diabetic - he required daily insulin later in life and then when he was about your kitties age I thought I was going to lose him( I'm sure you were worried sick too )
We had 7 more years after that so stay encouraged and work closely with your Vet( or see another Vet if you are not confident or dissatisfied in any way).....If he had 20 more years together it would not have been enough,you are in my heart and prayers
What's your kitties name?