Hi there
Please hang in there! I know how lonely / isolating this condition can be (or really any rare disorder)
Mine started 2 years ago (I’m in my early thirties). One day I was fine, the next day, BAM! I don’t know what caused it, but around the same time I was getting lots of migraines. I was so scared. Mine is face + hands + feet but my face is the worst for me. The pain was just all-consuming - I felt like I had to stop whatever I was doing to try to tend to the pain.
I told my PCP and she says maybe it’s stress-related. I never felt so invalidated! However, she did help me with the sleep issue 
I hated how I had to wait months to see specialist after specialist. I saw an allergist first, who said my tryptase is high (mast cells) but my condition was not allergy-related, and that I should see a derm or someone else
A friend of mine said once someone has to go down the specialist route, it’s going to be a long haul and she’s right. I saw ~5 docs but I now see a derm at UCSF and a derm at Stanford who are both helpful, thoughtful, and have experience with EM (and who are willing to work together).
I went through a lot of meds and didn’t have great responses. But I recently I seem to be doing ok on a calcium channel blocker (vasodilator)… knock on wood lol. I am more swollen but the pain has lessened considerably … Since my face is the worst, many docs wrote me off as rosacea and would send me away with some topical which of course did nothing. I was feeling so invalidated that my roommate offered to come with me to my doc appts, to help make my case and more thorough treatment.
You spoke of mast cells - I read a case study where antihistamines were helpful for a patient. OTC zyrtec was only temporarily helpful for me, now it doesn’t matter if I take antihistamines or not. Like my allergist said, I really don’t think what I have is allergy-related (esp. if there is pain?) My guess as to why the zyrtec was temporarily helpful: histamine is just one vasodilatory substance (which may or may not be released by mast cells) – there’s a lot of redundancy going on in the body so if it wants to produce a flare, it can fine-tune the amounts/sensitivities of other things so that you will flare. I’ve tried other heavier antihistamines (like taking 2 zyrtec + 2 allegra + benadryl + zantac) and no change.
I hope you get relief soon. Sometimes all you can do at moments is to take one breath after another.
PS Antihistamine therapy in the management of EM (revisiting the hypothesis) perhaps the increased dust etc while you were cleaning was a factor … I think unlikely, but just a thought.
PPS HRT/menopause and EM seems like I wasn’t the only one who got temporary relief from antihistamines