You have probably looked into high/low histamines. Looks like you are high histamine since you do well with anti-histamine (benadryl). Do the high histamine foods set you off?
Just my opinion but the histamine problems are of a much lower magnitude than heavy metals in your brain.
Wonder if niacin can help you calm down.
They used to give hyperactive kids ritalin, not exactly knowing why the paradox of an amphetamine would calm them down.
Worst for me was mercury and parasites as far as insomnia. But brain chemistry imo is too hard to figure with formulas, you have to keep experimenting to find what works. Have you tried low dose DMPS? Klinghardt claims that micronized silica is better, but I'm skeptical.
I hit the sauna very hard for years to reduce the heavy metals.
Short term benadryl sounds ok for emergencies but long term may not be so good.
Get yourself an outdoor kiddie pool and do the clay baths.