I would try to find a clinician who specializes in ADD, whether for adults or otherwise. I was fortunate to find someone 15 yrs ago who had that background (I was 35). This doctor sounds a bit out of his wheelhouse – he may be doing what he believes is best! Maybe he can refer you to someone?
I have found that other conditions often accompany ADD – like depression, anxiety, etc. Those cannot be overlooked, and must be addressed in conjunction with medication. I wouldn’t ‘pick’ a medication (I was switched early on from Ritalin to Concerta), but go with the proper diagnosis of trained clinician. Also, working with a trained therapist is essential. I originally thought that solely taking medication would ‘fix’ this ADD thing. It helped with some distractibility and other visible symptoms, but did not address the bad coping skills, shame and self-esteem issues that built up over a lifetime (I was lazy, spacy, etc.; all those things you mentioned above); those were the things that put my marriage relationship (now going on 25 yrs!) in jeopardy. I’ve found a therapist who really works for/with me; it’s hard work but I’m getting there.
I wish you well on this journey to diagnosis and treatment. The key is finding people with the proper credentialing, then building a relationship so you can begin the work. It’s hard work, but so worth it… CH