My guess is that you have ADD, and not ADHD. Many people seem to think that the hyperactivity is a required symptom.
Do some online tests yourself. I reckon that you will score high on ADD but low on the Hyperactive part.
A second diagnosis is needed.
The psychiatrist who did my first diagnosis concluded that I “just operate with a high level of stress”.
As for being ‘unintelligent’ as someone mentioned, a psychologist friend suggested that I do a Weschler IQ test. I scored 135+ using the 15 minute version. That surprised me, so I will do the longer test soon. >> http://wechslertest.com/