Some doctors can be real shitty like that sometimes. The medical community's understanding of ADHD has really evolved a lot over the past couple decades, but a lot of people are still stuck in the mindset that it's mostly in kids or that if you're managing your life then it's not worth worrying about. The good news is you can bypass them! Typically a good doctor will send you to a therapist for an eval, so you can just find your own to do the test. It usually takes longer to get an appointment, but if you can get with a psychiatrist and not a psychologist you don't even need to go back to a doc for meds. Psychology today's website is a pretty good starting point to find someone in your area that focuses on ADHA, and possibly even adults with ADHD. The diagnosis takes some time and often finding the right meds can be a long journey sometimes, but when you find what works it can be life changing.