This sounds all SOOO very familiar to me. Things that helped me (don’t know if they help you):
I was reminded that I am the one who is responsible for my health and that I wouldn’t be tortured by my bad conscience anymore if I just did anything. I took the first step. (Congrats on taking your first step, it is the most important one.) For me this was starting to log my numbers again. It forces me to sit down at least once a day to think about my D. And actually I joined TuDiabetes also to have something that would keep me on track every single day.
You’re on the right track. All the best to you!
Vera
P.S.: I asked myself “advice or sympathy?” and decided for advice. But be reassured that I’m as well able to relate to your feelings. 
