I’m sorry to see no one has replied to you since 2017 (edit: after I posted this it showed me lots of replies). I joined just to make sure you have since found resources. If not I recommend you look into the support website called insight and look under mast cell activation you will find several groups an one is the mastocytosis society who is also found at tmsforacure.org and also check out mastattack.com which is a searchable blog written by a scientist who turns out to be a mast cell patient.

Ps I was a mayo patient but after they told me I had a mast cell activation disorder they only were able to help me somewhat so I have since gone elsewhere and recieved more treatment and have a much better quality of life now.