Sean, Las Vegas is a problematic place for medical care, including challenging chronic disorders such as ADHD. Most people are from elsewhere and return home after short stays. That said, there is hope.
By all means, you must bypass undertrained personnel like the nurse who “evaluated” you. I recommend that you also look for an additional psychiatrist – or better yet, neuropsychiatrist – as a backup in case the first psychiatrist does not work out. I’m sorry that I don’t have any names for you.