Hi
@kittyscrafts , and welcome to the forum!
From what I've heard from others eating low carb, many of them dose for the protein as if they were half carbs. Of course we have no way to tell if this works for you, so please be very careful when experimenting!
A way to work it out could be to go slow. You already found protein spikes you when eating very little carbs, so you already know it needs insulin. The only thing you don't know is how much. So you could keep a log with the amount of protein you had and the amount of insulin you took until you find your insulin to protein ratio.
Good luck!