This is one I struggled with for a long time, especially in the early stages. It was so bad I had a nervous breakdown, pretty much. A lot of things had happened to me that year and I blamed it on that. Could I have avoided it, what could I have done different, what if etc......
I still struggle now, but I have learnt that I was probably on the road to being diabetic way before this and unless I had the inclination to cut down on carbs, I would not have been able to prevent it. If ever I felt the need to eat healthier, I would always have followed the low fat approach, which would never have worked, and I liked carbs too much!
I believe ultimately, it's down to genes for both type 1 and 2. We live our lives as we see fit but theres nothing you can do about genes. thankfully, at least there are ways to control it, but punishing yourself and looking for reasons why will drive you mad- put that energy into doing the right things now it's never too late x