Welcome. I think you will find that many of us have gone through similar feelings after diagnosis. It is something that you will need to work through. I look back on my diagnosis and think of it as a time where I basically "died" and had to go through a grieving process. I can distinctly note going through the five steps of grief outlined by Elisabeth Kübler-Ross in her "On Death and Dying." The five stages are D'Nial, Anger, Bargaining, Depression and Acceptance.
At the time, I really struggled with self-blame and fear over my upcoming death. In truth, my death was really about having to leave my old life behind. My death is years away and I am not helpless and I can live a long, healthy happy life. And eventually I came to realize that even if I had made some less than optimal choices in my life, my condition is primarily a result of genetics and environment that I had little control over.
You need to remind yourself that things will get better. You will regain your health. And you too can life a long, healthy happy life.
ps. Check out your legs and the pain. Maybe neuropathy, maybe something else. But remember, neuropathy can heal.
pps. People basically don't get complications and die from their diabetes, they get complications and die because they don't take care of their diabetes. It sounds to me like you are taking great care of your D.