[NoraWI]

The difference between T1/1.5 and T2 is the cause... an autoimmune attack for the T1/T1.5, and Insulin Resistance for the T2. The T2 also produces more than ample amounts of insulin which will generally cause weight gain.

Both Scratch and Helen are correct that a positive GAD65 antibody test will show definitively that you are T1 if your pancreas are still producing some insulin. Your C-peptide fasting test result of 1.3 is low but not definitive. Your high A1c at diagnosis, weight loss and no sign of either high blood pressure, cholesterol issues nor obesity are good indications that you may have the slow progressing autoimmune T1/T1.5, more accurately called LADA (Latent Autoimmune Diabetes in Adults) which can take months or even years to develop fully into T1 with no insulin production.

Adding exogenous insulin is a good way to preserve your beta cells although it is harder to control BGs in a consistent manner because your pancreas still make some although its release may be erratic.