Thank you so much for posting about the challenges you are facing! It's hard to ask for help and advice when you are feeling embarrassed (and probably a little ashamed).
You clearly have very high standards for yourself. Whatever you are focusing on, you want to do the best job possible! It's really hard to balance all the different priorities that are asking for your attention and for your "best" when you are in college!
There are other people here who have--or have recently had--the same struggles, and probably they can make more pertinent suggestions.
I would only offer that (although it's intense) college (and your grades and most of the people you know there) is only going to be a very short event in your life. And diabetes, and its affect on our health, and the results of the choices we make about it, are here with us for the long haul.
Thanks again for sharing and asking your help!
Wishing you all the best,