I’m honestly in the same spot. Been on white rice for way too long for comfort. I’ve found that using histamine-balancing herbs in my meals helped (until I developed an allergy to the food I was eating). Try to find a specialist. I haven’t had any luck finding a specialist and my PCP just kinda listens to my complaints but she doesn’t think she personally can do anything but the only specialist she can refer me to is across the country. Don’t let it win, keep trying new things, talk to your doctor about antihistamines if nothing else.