I'm glad you finally found a doctor who could help you. I think many of us have struggled with getting a proper diagnosis. I pushed for years to get the proper tests and move to insulin. I finally got the antibody tests, all negative. And my previous endo ("He who shall not be named") always told me I had diabetes because I was overweight and refused my requests for insulin. I eventually fired him and started insulin (gosh was that really 4 years ago?).
I had prepared for insulin for quite some time, as Terry suggests insulin demands respect. I bought "Using Insulin" by Walsh as Zoe suggests as well as "Think Like a Pancreas" and had read extensively. I still walk around with the label "Type 2" but it appears that my insulin production has declined markedly, my last c-peptide was 0.4 ng/dl which qualifies me for a pump. My current endo ("She who will gladly be named") now calls me "Ideopathic Type 1" sometimes called Type 1b. This category includes a type of diabetes called Ketosis Prone Type 2 where insulin waxes and wanes, but also includes other "undiagnosable" types.
I still wear the label Type 2 because Type 2 truly means diabetes of unknown cause. And that is what I have. However for my own sake I may need to hide behind my endo's classification of me as a Type 1 in order to get access to medical care such as an insulin pump or CGM as access is distinctly biased against Type 2s.