Congrats on beating it, PlaydohYeti! I'm still fighting the fog myself over a good few years, so I know exactly what you're describing and how alive you must be feeling right now. It's literally like you've been watching your life play out in front of you without being actively part of it.
From what I read, I'm guessing that you are gluten sensitive. If you can eat high-glycemic foods without much of a problem, then that rules out hypoglycemia as a possibility, in your case. You are either sensitive or completely intolerant to gluten, the protein found primarily in grains (and a lot of processed foods), hence the brain fog. The PB eating style contains no gluten anyway, so it's all good!
The day I feel clear-headed will be the best. I'll get there soon enough. See you around!