Do you attend dietician educator meetings with him? It might be helpful to address this behavior of his with the educator ... because he is literally killing himself.
I have the best luck with my husband (who, admittedly, does not have diabetes) when I prepare his food for him, dole out small but healthy treats, and so on. I try to keep the overall tone light and affectionate, and if he gets mad at a restriction I uphold, it usually doesn't last long. Also remember that highs and lows of blood sugar can cause erratic emotions, behavior, and even cognitive clarity.
Anyway, tomorrow is a new day and I hope you sleep well tonight.
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A finger in every pie.