A good post on how to use antibody tests to diagnose LADA/T1 was written by our member @Melitta. You won’t typically be diagnosed LADA/T1 until your c-peptide is low (you need to know your blood sugar at the time of the test). The insulin autoantibody test is only one of the needed tests and yours was negative.
Technically there is no “in between” type of type 1.5. Most people consider LADA to just be adult onset T1 and that it typically will have a longer honeymoon (possibly even a decade). There are many types of diabetes (including things like MODY) and type 2 diabetes is very heterogeneous. It is appropriate to get a complete workup of all the antibodies to be clear.
I find the stereotypes of diabetes really disturbing. If you are older and even the slightest bit overweight you automatically get diagnosed as T2. Here it is, nearly a decade later and now after having complications you are finally having the medical system spend a couple of pennies and minutes actually bothering to diagnose you.
You may well have been T2 all along, but that doesn’t excuse not asking important questions. And no matter what type of diabetes we have, we have a right to proper treatment. And I’m sorry, an A1c of 6.6% isn’t normal and the fact that you now have complications suggests that you might have done better with a better diagnosis and improved control no matter what type of diabetes you have.