Not at all surprised that you feel better when consuming some meat. Dr Hal Huggins, a pioneer in mercury free dentistry, said he stopped taking vegetarians as patients. An internal review of his success rate with them was too low.
The sickest of the chemically sensitive people in the detox groups often just tolerate a dozen foods, things like organic chicken, rice a couple of vegetables, etc.
Gluten free diet and GCF are two of the more common diets. Paleo seems to be more hit or miss. The former two were highly regarded for parents of autistic kids in this large survey. Notice that heavy metal detox--chelation--was the best rated intervention. http://www.autism.com/index.php/treatment_ratings_asd