As soon as you can feel you are going low, immediately do something about it, eat suger. It dosen’t matter if you took insulin for your meal and “you just need to finish the meal”, dosen’t matter, now you are going low and need sugar. period. Then you can finish your meal and take more insulin later if you need to. Postponing action feels most comfortable sometime, but move away from this mindset.
Take a break from what you are doing and try to calm down. I usually become a bit manic and hyper active when I am going low and the signal of being low is an indicator for me to sit down, eat suger and try to relax until I no longer have low blood sugar.