I think the flushing very well could be from mast cell issues or allergy related events. Did you ever track if there is any pattern to the flushing? Do you take Zyrtec and Zantac or other antihistamines? Excessive yawning may be a lack of oxygen in the blood or a vasovagal reaction. Your other symptoms make it sound like bad dysautonomia/your nervous system is in overdrive. I am so sorry you are going through all this. I hope you feel better soon!
Ang.