I don't mind sharing at all, but again in full disclosure... I am NOT a doctor. Sheer desperation drove me to the internet in search of answers.

This is the article that I found so helpful and it includes the medication recommendations and possible dosages to try.
https://hoffmancentre.com/mast-cell-activation-syndrome-histamine-immune-system-runs-rampant/ As is suggested in the article, I use Zyrtec (ceterizine), Claritin (loratadine), PEPCID (famotadine) and quercetin all 2x a day. (Regarding Quercetin effectiveness- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3314669/ )

I definitely recommend keeping your doctor involved in all medical decisions, for safety of course, but if for nothing else just so they can document improvement.