The best thing I found to cure insomnia is vitamin B12. It makes total sense too, because B12 is vital for the production of serotonin and melatonin, amongst other things. These are critical for regulation of sleep/wake cycles, mood, energy production, and lots more. Also, those with Celiac Disease are very often deficient in B12, so there again it makes sense. I find I sleep quite well now, especially if I take the B12 about 30 minutes or so before I go to bed. The one I prefer is a 5mg methylcobalamin sublingual tablet made by Source Naturals.
Other nutrients are also helpful with sleep. For instance, magnesium is known as the calming mineral. And interestingly, people with Celiac Disease often have a deficiency of magnesium too. A co-enzyme B-complex can also be very helpful, as can a multivitamin/mineral, so I'd suggest these as well.
All of the things you say are true! One other thought is the Candida issue. My son wakes up in the middle of the night( and never seems tired at bedtime) whenever his Candida grows out of control. Our naturapath doctor treats him with an anti-fungal for systemic yeast and he is feeling right as rain. Just food for thought!