Do I need an evaluation for ADHD? Yr)

As a child, I never liked reading novels, but always like encyclopaedias with random facts. I never studied from textbooks or made notes bc I absorbed everything in class & wrote whatever I could remember and was graded well. I was called gifted. But as I turn 20, and in engineering, trying to pursue a career of research which requires deep focus, tolerating uninteresting topics, long reading sessions, seems like a daunting task to me. I worry that if I talk about this specifically to a psychiatrist, he/she would feel I am faking it or extensively coming up with the right symptoms to fit the disorder. Recently, combined with the general hyperfocus periods on interesting tasks and disinterest & lack of drive for routine & mandatory tasks I have been experiencing brain fog, mood changes, and withdrawing from interactions, because they seem too much. I know I need help, but I do not know if my symptoms are real or if I'm exaggerating unintentionally. (History, diagnosed MDD, last yr)