I think it is hard to say without knowing your entire background/symptoms. It sounds like you experienced quite a bit of early trauma as a result of your fathers beating. PTSD can definitely create similar symptoms to adhd.
I can’t say whether your psychologist is right or not but if you invested so much time in testing why not hear what they have to say. What is their plan for treatment? It sounds like you shut down and may not have been able to process what they were saying. So maybe write down all of your questions and have the psychologist answer them. Also, was the psychologist culturally similar to you? If you do choose a new provider maybe find someone with a culturally similar background who may be more culturally competent (i.e. you wouldn’t know of a family history because there is stigma attached to mental health issues).
Good luck. I know it’s not easy.