Avoid sweets and stay as close as possible to a paleo diet. Sugars can destroy your energy level while creating a compulsion to eat more sweets because they make you feel good.
Food allergy type problems are cause of much emotional distress in modern society, in fact allergies are the single most significant yet underdiagnosed problem related to emotional health.
Cats for instance are basically suicide for people who are allergic (this is what happened to me).
Protein Power Lifeplan, and Breaking the Vicious Cycle are great starter books for paleo (latter has to do with digestive problems but the treatment is identical)
Good luck.