(?) Flat reading do I increase dosage again?

I have increased Mango's Prozinc and today we again have readings today that are flat. As you can see from the SS our Vet increased the Prozinc after curve on 7/10/19 from 2.75 to 3.75. On the curve 7/21/19 Vet said to keep the dosage the same. Days after that the numbers have been horrible. On 7/29/19 the reading were flat and according to the sticky notes for Prozinc I increased dosage .5 unit from 3.75 to 4.25 units. For two days the readings were still high so I decided to increase dosage again .25 units so we are now at 4.5 units. It's not helping to bring down the BG. Today the reading are flat again. I feel like a complete failure as I have no idea where to go from here. I will do a curve for the vet in the next couple of days and did not consult him as he is out of town. I do not understand why on raising the insulin dosage the number are still high?? I am beside myself questioning my direction with Mango's BG. Mango is feeling really good even with the high BG. Tested for Ketones and it's negative. He's gained 1/2 of weigh from our new Vet visit on 6/15/19 when we were switched for Vetsulin to Prozinc. Please help me understand the what and why I am having such a hard time with regulating Mango's BG. I am so lost. I need your help. Do I increase dosage again with the flat readings today?

 

This is cross posted on ProZinc forum: http://www.felinediabetes.com/FDMB/...-increase-dosage-5-again.217817/#post-2420365 I responded there.