Are you able to eat any of the starchy legumes? (starchy beans, like pinto beans or navy beans)
At least one serving of those per day improves my response to even the most perfectly allergen-free diet. Avoiding the allergenic foods and fructose wasn't enough for me - I also need the slow-digesting long chain starch and soluble fiber in these legumes to really improve matters.
I've suffered from unexplained sudden onset hypoglycemia for decades, not chronic like many people on this thread. But maybe this tip will help someone.
If people have allergies or something to legumes, perhaps some combination of another soluble fiber, (like psyllium, pectin, or guar gum) mixed in the same meal along with any complex starch food that they are ok with.
There's another idea, in the first post on the following thread: "Resistant Starch", which is different than the legumes/soluble fiber thing I just mentioned. Here's a thread on resistant starch, but the advice out there is if you try it, start out with just a tiny bit, not the large doses the first page of the thread mentions: