Diabetes is a big deal.
My experience has been that people don't get it at all or they want to tell you about their [fill in the blank] who had diabetes and didn't take care of themselves and lost their [eyesight, foot, life, etc]. Both responses are borne from a lack of understanding and in some cases, a lack of compassion.
When someone gives me the "you'll be fine, stop complaining" line, I've taken to asking them to consider my side of it. I have to live with this everyday and it affects every aspect of my life, not feeling well is going to happen and I will most likely mention it again, and if they have a plan where I can feel better I'd sure like to hear it. It's confrontational, yes, but sometimes I feel I have to be confrontational to defend myself.