Hello side, dont think I'm a spammer please :/ ( as i commented a lot today) but I dont think its correct for your "other docs" not to care or examine ADHD further, as many of us present insomnia and anxiety problems just as you, in fact my self took for a serious period of time melatonin to cope with the sleep issues, and i know many others that still do it.

So, they might be influed in some way by the fact people are worried about over diagnosing, and over medication, which i still dont understand, leading to more and more doctors not to give a f*** for actually people affected with this disorder.
So in many legit cases, as your self, doctors just dont want to sign up a paper for an ADHD medication, because that can be identified as "non serious medical practice" because this media issued i said before.
Talking about your experience with ritalin and amph, those frequently help, but, there are other options such as atomoxetine, but if you have liver problems you should forget about what i said. In case of farmacological approach being a failure ( due to your age, as you descrbied) you should consider herb and supplement aid, it is far less effective, but it has been shown to improve somewhat ADD issues.
Sorry for being an spammer and hope any doc to take seriously your ADHD problem, as it can be very problematic and frustrating for the patient :/