Luckily I was put on insulin fairly early, 4-5 years after the first fluctuations, long acting at first and then when my numbers kept getting worse fast acting was added. I was commonly in the range of 11-25 before a fast acting insulin was added and never felt bad from it.
I thrived once I was on both types of insulin and seemed to have escaped any problems from it. It wasn't until I switched doctors that a fast acting insulin was added and then she sent me to the new endo who was hired who tested me right away. 9 years of being misdiagnosed.
It is still aggravating to think of the fact I had a very healthy diet being as how I was a vegetarian since I was 11, and a vegan of 20 years at that point, I swam 75 laps in a gym pool 5 days a week, had an uncle that died from type 1, medications didn't help much and made me sick, but I figure because I wasn't skinny it was assumed I had to be type 2.
The old endo should have especially knew better and at least tested me when I asked about it, you know what the first GP's comment was? The medications wouldn't work at all if you were a type 1. A doctor said that and I believed her at the time.
So much misinformation out there and it's scary to think a doctor thought that.