Marcy...sorry to see that you are having such a hard time with the regulation.
I use Levemir for both my kitties. Both of them will bounce when numbers get into a low/lower range than normal. One of my kitties is a real bouncer and it can take several days for the bounce to settle. He was diagnosed in November 2014, so very close to when Oyster was diagnosed.
One thing that would be most helpful would be to have an updated spreadsheet, since there is no data since early February. Insulin needs can change on a regular basis so it is impossible to tell what is happening at this point in time without more information. From what you described it
may be possible that the current dose is taking Oyster too low and then the bouncing comes into play. Also from what data you already posted it looks like the dose was being changed in larger amounts up and down. Levemir works best with a consistent dose and small dose increase/decreases.
19 is a senior kitty but still not too old to continue treating him. There are members on here who have kitties that are 20++ years old with diabetes that are doing fine. It is all about the quality of life. If Oyster is still eating, drinking, playing. pooping. peeing. grooming and enjoying his time then it is certainly not time to think of letting him go. Getting a better handle on the diabetes treatment program would make you and Oyster feel much better. My Tuxie who has been diabetic since November 2014 also has other health issues which make treating the diabetes more challenging, but he is still doing well overall and I will continue with his treatment for as long as he has quality of life. I understand the frustration of bouncy numbers but don't give up.
I note that you free feed Nutro Max Natural Choice Dry Food. It would really be better...if possible...to remove all dry food from his diet and just stick with the low carb wet food. Dry food has higher carbs and with many kitties that are especially sensitive to carbs it can cause glucose numbers to jump up.
You will get more attention on the Lantus/Levemir forum:
http://www.felinediabetes.com/FDMB/forums/lantus-glargine-levemir-detemir.9/
If you could update your spreadsheet and do another posting there with the information you put here there are lots of experienced users that can assist you with the best direction.
