Happy to hear you've adjusted your diet. I know so many diabetics and pre-diabetics who continue to eat whatever they want because they have medication.
Online "experts" are a dime a dozen, but this is one the seemingly most informed and best sourced pieces I've seen on glucose. When I first realized I had spiking problems despite an a1c and FBG in the normal range, I had to look long and hard to try to learn what that meant. I haven't looked in quite a while, but this article was written 3 years ago, and I'd not seen it.
When "Normal" Blood Sugar Isn't Normal (Part 2) | Kresser Institute
This passage below in particular is the big concern. Despite my perfectly normal a1c and FBG, I will spike ridiculously high (I've seen as high 288) when I eat high carbs and can stay at elevated levels for well over two hours before making its way back to normal.
"If post-meal blood sugars do rise above 140 mg/dL and stay there for a significant period of time, the consequences are severe. Prolonged exposure to blood sugars above 140 mg/dL causes irreversible beta cell loss (the beta cells produce insulin) and
nerve damage."
I've used a meter to learn what I can and cannot "get away" with carb-wise.