Wink was 12 when he was diagnosed and had been abandoned at a cat shelter and was in absolutely horrible shape.
If he can bounce back and run around like a kitten, your cat can get back to their old self too.
We've all been where you are now. We understand how stressful this diagnosis. You have taken the first step when you said your kitty deserves help.
Yes, if not on insulin yet, a change to a low carb canned food like the Fancy Feast pate (classic) style, Friskies pate or Wellness grain free can make a big impact on those BG (blood glucose) numbers.
Please tell us a bit more about your kitty and then pop over to the Feline Health (The Main Forum) to ask any questions you may have.