I would be careful about trusting the stated carb count of a protein powder. Sometimes they "lie" and it contains added sugars that they don't count. Look carefully through the ingredients.
Second, remember that you may need to bolus for protein. I consider that half the grams of protein are converted to glucose, so I bolus for half the protein as carbs.
And finally, where is the fat. You absolutely need fat. You should be eating full fat yogurt and milk and even adding fat. Consuming a high protein diet with low/no fat can result in protein poisoning (also called Rabbit Starvation). You need to be careful, perhaps you could add coconut oil to your shake?