If I remember correctly you do have unusual symptoms for T2!
I believe that I do understand or it is something that occurred to me through my battle with hyperinsulinaemia and insulin resistance and high glucose levels.
Because the glicizide helps your glucose levels to go lower, it is now reduced in how quickly your levels drop now. You should by now reduced your insulin resistance and the need for excessive insulin has reduced, so the fluctuations are less severe, that must help ease your symptoms. If your fasting levels and hba1c levels are near normal, the need to lower your dosage is necessary.
In other words, the reduction in meds has reduced your symptoms.
And of course what you eat and how much dictates your glucose levels and how much insulin is required for that glucose!
Best wishes.
Or I could be totally wrong!