Welcome to the forum, Yogimama. It sounds as though you are trying all the right things, and your doctor did the tests to rule out other causes of flushing. That's good! However, you're having trouble finding an H1 antihistamine that doesn't cause your heart to race, and you haven't found anything to help with the flushing. (Correct me if I don't have that right.)
I have several thoughts. H1 antihistamines are helpful if you're having anaphylaxis, but they might not resolve every symptom. If your PGD2 is high and you're flushing, you might want to try a medicine that blocks prostaglandins and see if it helps. For me, an extra strength Tylenol (500 mg) stops the flushing symptoms (also cheeks and ears) I get when my mast cells degranulate. If you can tolerate salicylates, aspirin might be a good choice instead of Tylenol, as it also blocks prostaglandins.
Sometimes H2 histamine blockers, such as Pepcid or Zantac, are helpful for a number of mast cell symptoms. Most people take 20 mg. Pepcid or 150 mg. Zantac, twice a day. Some people take double those amounts. Do check with your doctor before you try any new meds. Don't take more than the recommended dose of Tylenol, as it can damage the liver, especially if taken when you've had alcohol.
Another medicine that was helpful to me when I first became I'll with this, is doxepin. It is both an H1 and H2 antihistamine. It also helps to relieve stress and will get you into stage 4 sleep if that's an issue and if you take it at night. It requires a prescription. You do try new meds only when someone else is around, I hope.
Finally, do you carry Epipens or the equivalent? If you've had anaphylaxis, you should carry at least 2.
Different doctors believe differently about what a normal tryptase level is. The labs usually say up to 11 is normal, but some experts in mast cell disorders believe that anything higher than 1 is abnormal.
You have had exposure to a number of things that can cause mast cells to function abnormally, e.g., exposure to mold and spider bites. Stress is the biggest degranulator for most people, and who doesn't have stress!
Have you tried an actual elimination diet? There are many out there. I like the low histamine diet, because it eliminates foods that are naturally high in histamine as well as those that actually can cause mast cell degranulation. Essentially, you stay strictly on the diet for at lest 10 days. Then you add back in foods, one at a time, every 2-3 days. Usually people react very soon after adding a food, so it's apparent which one is causing a problem. The diet I like is on this website:
http://chronichives.com/useful-information/histamine-restricted-diet/I get vocal chord problems from time to time. Don't know why, but think it might be GERD, too. Don't know what to do about it, unless it proves to be reflux.
If you have specific questions, feel free to post them. If you feel your doctors have not adequately diagnosed you, check the listings on here about competent mast cell disorder doctors.