Hyperactive 5 yr old!!!?

hi my daughter is extremey hyperactive to the point she can be sick when jumping around.she runs across roads and has no danger awareness whatsoever. the school have raised several concerns due to her behaviour and violent temper (hitting a child across the head with a rock in school is the latest) because she was playin with someone else. she is on the verge of being expelled so i decided to join a parenting course for behaviour help which doesnt seem to deal with much past the point of shouting tantrums and 2 yr olds biting. my daughter has 9 months to wait to see a behaviour officer in school for some testing but i would really like to see if there is something else we as parents can do. we have cut out all sweets, crisps, pop and chocs in her diet and are now looking in to e numbers. i have read about evening primrose oil and omega 3 supplements. can anyone recommend anything or have tried these tablets on children. i will obviously speak to m health viitor before giving her anything but she is on a two week annual leave. please help. thanks