Hello,
It is not safe to increase or decrease the dose of Insulin on your own without medical supervision as it may cause fluctuations in blood sugar levels which may have dangerous side effects.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
There is no correct dose of insulin or typical for any person. The correct dose for you is the dose that controls your blood sugar well.
Eating a lower carb diet / exercise may also help in reducing how much insulin you need to take.
If you are on such a high dose, you may also be dealing with insulin resistance. You may ask your Dr whether you can try an insulin sensitising drug such as metformin. However, this should be done under close medical supervision as taking this drug may mean you need to reduce your insulin dose.