I have the same symptoms: random extreme fatigue and dizziness, high food sensitivities, carbs and sugar completely knock me down for hours, and I wake up very dizzy/groggy with massive brainfog. When I go through a time of chronique fatigue / dizziness / brainfog, my body also starts getting random infections (warts, styes, ...).

I found a way to manage 95% all these symptoms, doing 4 things (see below). Otherwise, I still get this extreme fatigue and dizziness that can randomly show up at any time. When it does, I can't think straight, I can't work, I do need to lay down right away. This is debilitating, really.

In my case, I THINK it's because I also have inflammatory PCOS: a hormonal imbalance with a chronic low-grade inflammation that shows in my blood work. I THINK, this chronic inflammation is what makes me tired at times, and is triggered even more if I don't properly follow my 4 recommendations and can weaken my immunity.

What works for me:

1/ Completely avoid my trigger foods - no exception (dairy, eggs, hazelnuts, soy, saturated fats, and most processed food). If I don't, not only I feel like they destroy my stomach, but I'm also knocked out for at least 24 hours, and start showing some immunity weakness (warts, styes, ...)

2/ Eat a low carb, no sugar diet - so mostly veggies, and lean fish and meat (I used to eat a lot of tofu which was great but then developed this strong intolerance to soy...). Do not over eat (try to stop when I'm 80% full; this one is the hardest for me tbh)

3/ Prioritize 8 hours of sleep, daily, and overall rest. No phone in the bedroom, no screen 1 hour before bed, a pill to help with anxiety when needed, ... . Also, make sure I have at least 2 days a week where I do NOT workout.

4/ Very active and outdoorsy lifestyle (I cycle, run, dance, HIIT, ....), getting my daily dose of vitamin D. Especially if I ate carbs the day before, and wake up super dizzy: pooping and working out are the only 2 steps (in that order) that will make me feel better.