If you were fit and healthy at diagnosis that may be why doctors would assume you weren't type 2 because, usually, type 2 diabetics do not present as fit and healthy at diagnosis (notice I say 'usually' and not 'always') hence why they leaned towards type 1 at the time.
Do you know what blood tests have been done? In order to find out whether you are type 1/1.5 diabetic you need a c-peptide and an antibody test carried out. Type 2 diabetics usually present with very high insulin production and test negative for antibodies. Type 1/1.5 is the other way round - low insulin levels and positive for antibodies, particularly GAD antibodies.
It may be that you are LADA/1.5 which is slow-onset type 1 and sometimes going onto insulin immediately can result in increased insulin production. Even if you don't take insulin this can still be the case as my insulin levels were 395 at diagnosis and 6 months later were 750 and I have never injected insulin.
A lot of people on here have been diagnosed as type 1 and put on insulin and then, after a period of time, have hit a 'honeymoon period' where they produce more of their own insulin which diminishes their need to inject it....
Alternatively you could have just been suffering from IGT (impaired glucose tolerance) but your level at diagnosis being 'sky high' would perhaps suggest LADA.... Have you had a hba1c done as this is usually diagnostic of diabetes?
Diagnosed with GD in 2010, Completely disappeared postpartum. Re-diagnosed December 2012 with type 1.5 diabetes, age 26, BMI 22 currently controlled by only Metformin, 500mg twice a day.