Hi M.,
First of all, I sympathize with what you are going through. The great thing about you as that you get that your daughter is struggling and you are not assuming she is just a pain or a bad personality. So many people make that mistake.
Your daughter clearly has the genetic setup to be effected - that absolutely does not mean you cannot turn it around. My son is recovered from Asbergers (grandfather with manic, uncle with adhd). He is a beautiful testiment that with dedication and education and lifestyle and medicine (not, not class 2 drugs), she can get rid of this.
A couple of things I might recommend:
1) Read the Sensory sensitive child book. This will help you understand what events in a day that are setting her off/causing her discomfort and thus, act out (bright lights, colors, too much noise, etc). You might be able to spot what about school is sending her over the edge and perhaps accomodate it.
2) visit and scour www.generationrescue.com
3) read "Healing the childhood epidemics" by Kenneth Bock, MD
4) Based on the medical recovery of my son (using conventional and alternative treatments) , I have learned that ODD, OCD, ADD, ADHD, dislexia, Bipolar, Autism are all based in the same root problems. There are a set of problems that are different for each individual genetic makeup per child, but cause the biochemistry of the body to alter (causing neurotransmitters to be off, causing the nervous system to fail to work together, etc). As you read, read for information without getting caught up in the diagnosis or even the direct behavior.
5) Many celiacs report having these types of problems prior to being diagnosed, many children are not qualifyable celiacs, but react to gluten and casein with violent styles of behavior. Many children only 1 month off gluten and casein will see drastic improvements. Search GFCF in the web to find much info. There is a doc called "10 weeks to GFCF" by an organization called TACA that is fabulous. It can be tough, so this step by step process makes it doable and it can be the single best thing you can do in the beginning to start treating her.
I could type all day, but please know that this disorder, as well as many other childhood disorders, are based in a physical, solvable (albeit with much work) problems.
Thinking of you and praying for your patience.
J.