Is this Frazzled Parent Syndrome or something requiring more thought?

Thanks, Suzeb1. We have pretty definitively determined that artificial colorings and even just raw sugar exacerbate the problem. The holidays unfortunately provided a lot of opportunities for experimentation. We live in a country without much in the way of dairy or gluten substitutes and where doctors are a bit behind the times and tend to just throw drugs at you, so we're more or less on our own in trying to determine food sensitivities. One thing that I see as an issue is that her behavior is much much much better at preschool than at home. I know that happen sometimes with kids with emotional stresses. They can keep it together for part of the day and then tend to let it all out where they feel safest (at home). But it tends not to be the case when food sensitivities, processing or ADHD are the major factor. That said, I'm still not convinced there isn't more going on than emotional stuff. Recently, she has been most focused on stuff and everything being "mine". I know that happens with preschool age kids but I've never seen it to this extreme. That sounds like attachment issues to me objectively, but she certainly doesn't have the kind of easily identifiable attachment issues our son had and has largely worked through. Thanks for the advice in any event.