Glucose is reading higher and urination is still frequent u

After my cat's curve test my vet updated his glucose to 2units from 1u on his Lantus. I just got his glucose monitor in and his ranges are showing over 500, which is worse than two weeks ago. I've got him on a low carb high protein fancy feast pate as recommended by many in the group.

He gets his 2u twice daily.

He is drinking a ton still and is not fully going in his litter box. He will get in it and end up urinating over the side of the box or he just pees on the floor outside the box. I started putting pads down but im afraid I'm now encouraging him to pee out of the box.

I'm just at a loss. I'm not sure what I can do to help get this into range to help alleviate his symptoms. I'm going bonkers with all this urine. He's actually in very good spirits and actively playful. I'm at a loss. outside of dietary changes and glucose, what else can I do?????