Since it's almost time for my bed, I will write down what my plan would be for tomorrow. You don't have to follow my advice, of course, Tux is your cat and you must have the feeling that you are doing the right thing for him. It's all your decision.
I would switch him to the wet food you bought, tomorrow morning (during daytime you can better monitor him). Usually the feeding advice is about 350 to 400 grams a day? I'm not familiar with your weight indications, I'm used to grams. No dry food anymore. So 35% would be appr. 140 grams wet food. I suppose he's hungry as he is so high in his numbers, so I take the 400 grams as a starting point. Please, convert the amount to the weight indication you are used to.
My advice is:
- test his preshot level
- give him 140 grams of wet food (35% of day quantity)
- after eating at least 100 grams (but preferably all), give 1 unit caninsulin 15 minutes after eating.
- do NOT feed him afterward, take away the leftovers (if he ate at least 100 grams of wet, it's enough)
- test +3, +4, and so on every hour until the level rises again on its own (without food or snacks, you may only give him 1 small chunk of meat, cooked or raw, after a test)
- when his level has risen without help of a snack or food since the shot, you can give him 60 grams of wet food (15% of day quantity)
- only if he drops under 72, you should give him the food immediately and not wait until the level rises again. But I doubt he will drop that low.
This way we will have an indication of where and how low his low point is at this moment, although it could change some time after the food is changed.
We'll decide on a new dose after seeing tomorrow's levels. If the food is changed to even lower carbs, maybe we'll stay on 1 unit, or go only to 1.25 unit. It all depends on waht we'll see tomorrow.
I will be online tomorrow around this time and earlier, but it's 11.30 PM now here, so I'll be off to bed soon. If tomorrow he drops under 72, I'll stay online longer to help.
Buy enough cans of food to last a few days.