My doctor is warning me that insult injection does damage to pancreas

I have been a type two diabetic for the last couple of years and have been maintaining control with metformin and glyburide up until a few months ago. I also have two type 1 diabetic sons, so I have been living with diabetes for well over twenty years. I live on a low carb diet (around 100 grams of net carb per day) and am fairly active.

Several months ago my oral medications stopped working well and I was unable to get my BG down below 200 even on a 0 carb diet. I was unable to get in to my doctor for several months (we live in a remote region) so I started injecting H to lower my BG. It worked wonderfully well, so I went off my oral meds and moved to insulin therapy. (mix of H and N at breakfast and dinner). It has been working very well, with my BG routinely staying between 80 and 120 testing about 4 times a day. 

Here is my question...My doctor now wants me to move back to a different oral medication (which I am ok with) but she is saying that insulin injection over time will destroy the pancreas and beta cells! I have never heard that in my decades of following diabetes treatment and can find no evidence of that in any current research. Have any of you folks heard or read anything about this? Is it time to find a new doctor? (She is a GP, not an endocrinologist) Any help or thoughts would be appreciated

Thanks

Bob