Both mum & myself are problem sleepers, some nights I can sleep from 9pm-7am through & still wake up feeling like I haven't slept a wink. Mum is also Coeliac, I was blood tested years ago & it was non conclusive at that stage. I've had 2 full blood counts done last year, 6 months apart, all my levels are fine except my Iron/B12 levels which had dropped. Wow Meow! That's terrible but thanks for sharing that as it fits with my mum's depression/not depression struggle & mine as well. Both of us have back/muscle issues as well. It truly terrifies me that I'm walking the same path as mum, it's not an environment I want for my children & husband
OK - as someone who nearly had antidepressants pushed on me over the course of several years but finally insisted on getting a sleep study done and SURPRISE have a significant sleep disorder (narcolepsy) this is what I want you to know: depression (/bipolar) can cause sleep disturbances but likewise sleep disorders can cause depression. (Just read that last bit again). Talk to your doctor about getting your sleep checked out. Also, get your Vitamin D levels checked, and if they are low, start taking a supplement along with some magnesium & if you don't have much dairy in your diet, some calcium as well. Just take your iron supplement (with some vit C to increase absorption) at a different time. Vitamin D/magnesium/calcium are all needed in order for the correct sleep hormones in your brain to switch on, and without it, your daytime/nighttime circadian rhythms might be out of whack.

BTW - a full blood count will not screen for other fatigue related issues, the dr needs to order a number of different tests (and they take about 6-7 vials to do it) so you need to be asking specifically for tests relating to thyroid, vitamin d, blood nutrient levels, inflammatory markers, etc.

If mum is coeliac, she may be having some accidental glutination happening (ie when you eat something that looks like it *should* be gluten free but really it's got some tiny amount in the ingredients list). You could try going low- or no-gluten, and see whether you get any improvement, as it is possible to have gut damage without having the clinically required test results. If going gluten-free for several weeks improves how you're feelign, that may be a sign that you need to be screened again. Either way, anything you do to help improve your gut health (eg, GAPS or leaky gut diet, pro-biotics and pre-biotics) can't harm and is worth a try.

ETA - Meow, I'm so sorry to hear about your mum. So, so, sad