Aubrey, you might need quite a lot more estrogen before concluding that it's not estrogen related...
" I've tried increasing the Sandrena but it doesn't change anything. I had an estrogen blood test while I was using 2 mg and it was 292 nmol or pmol, so quite low, so I increased dose to 2.5 mg."
So, firstly I have it from 3 different Newson Health doctors I've seen over the past 3 years, that many women need estrogen between 450-650pmol to fix symptoms, especially during peri-menopause when often higher E is needed than post-meno. (To over-ride fluctuations.) This goes especially for insomnia and neuro symptoms. 292pmol is very low, only just over the 270pmol you need for bone protection.
Whilst you've added another 0.5mg, you haven't tested and there's no guarantee you have actually absorbed anything additional with that increase. (In my case, I had the same serum estradiol on 6 pumps of Oestrogel as I did on 12 pumps of Oestrogel.) A dose increase does not always = a serum estradiol increase. And even if it did, you only added 0.5, which isn't going to bump you up 200pmol...
Secondly, our own estrogen is all over the place during peri and your own ovaries can contribute more and affect test results. You might only be getting (say) 50 from HRT and the rest might be from yourself - which cuts out down to 50 when your ovaries cut out. (As happens during peri.)
So I really don't think you've explored the whole estrogen side of things thoroughly. It might not be the answer, but really it needs to be tried to be ruled out and there is no reason not to trial getting the serum estradiol higher into 450-650 range.
I say this as someone who is trying to do the same thing, for the same reason. For me it is hard because I don't absorb well transdermally so I need high doses. On 6 pumps of Oestrogel (and on 12!) I had about 325pmol. I am now on 100mcg Estradot patch as well as 12 pumps of gel, but I'll be coming down on the gel as I go up on the patches.