Just thought I'd give an update to this thread (and thank you for your kind wishes Tora).
I am now more and more sure that the Urticaria and intensely itchy eyes (it feels like Urticaria IN your eyes and is accompanied by overwhelming fatigue) are connected to my hormones, and it's appearing that it might connected to the balance between E & P. I did a couple of experiments - the first I've already talked about with switching to the patch which involved an increase in E, the second which involved adding an extra spray of my Lenzetto (now I'm back on it) and both times it caused a flare up in my Urticaria. Separately to this a massive flare up also coincided with my pre ovulation Estrogen surge.
The confusing thing for me is that the periodic eye symptoms (which are totally part of the same thing and equally as unbearable as the Urticaria and I mostly experience during the first week of every cycle) were present even when my Estrogen dropped to 300 back in December/Jan, which for me is a very low level. They were also still present when I managed to reduce my Lenzetto to 2.5 or 3 sprays a few months ago. The only possible thing I am left to think of is that while I need a certain level of E to function, it's possible my Progesterone level isn't high enough (especially at certain points in my cycle) to balance it out and it's causing this excess of Estrogen and histamine. I know from tests in 2018 prior to Peri that BOTH my Estrogen and Progesterone were over the top of the range naturally throughout my cycle, and the last time I tested in May my Prog was just under half of the midway range (day 21).
I tried one day of adding the extra Prog on the first day of Utrogestan but because I was so highly symptomatic with the fatigue and everything else I didn't feel I could continue - I feel like I need to be relatively stable to be able to assess what is side effects from what. The last two days (day 16 and 17 of my cycle) have been a bit better so I may try again adding the extra Prog in tonight. I'm now also thinking of being brave and trialling (not this month) taking some of the BHRT Progesterone throughout my cycle, so as to better balance E & P but I'm nervous about potentially preventing ovulation by doing so, as when this happened when I trialled the BCP before HRT it caused me all sorts of problems and symptoms, my body was very unhappy. Crispy have you tried taking Prog throughout at any point?
Sorry for the lengthy update - I just feel I can't be the only woman who has or will experience this and I'm hoping by sharing my findings it might help someone else! I've also been doing the low histamine diet (except for 3 cups of tea a day) and no gluten or dairy, but it hasn't made any noticeable difference yet.