I developed this in 2018 as well and I'm using all the meds you are. Your symptoms and outbreaks sound just like mine. For the first couple of years nothing touched it. I use 600mg Xolair/month, Triamcinolone cream and the rest..hydroxyzine, allegra, ice packs directly on my skin, etc and nothing worked. As of 2 years ago, my outbreaks are less often and much less severe, so now those meds sorta help but once a year, January, the worst outbreak occurs and nothing touches it again. I wish I had better info but it doesn't exist to my knowledge. It sounds like we're all doing the same thing with the same lackluster results.