Two points I hope help you:
My personal belief is not the same as your wife but similar: As a long time ADHD adult, I've come to believe ADHD is a societal problem not a mental illness. It is a version of humaness. This is my experience and I don't expect others to accept it. But, there is a psychological concept that if you remove societal pressure to "be" a certain way, and you are allowed to be you and the suffering is alleviated, its not mental illness.
That being said, you are a grown adult who is allowed to decide what you need. Your wife is being borderline abusive if she is using those actual words and threatening consequences. If you believe this is your best option, put your foot down, thank her for her opinion and say you're doing what's best for you and ultimately it is your own choice. Be prepared to be met with threatened consequences if that's a thing, and try to have the courage to say something like "Threatening me is not acceptable, and I'd like you to work on that issue. If you are unwilling to try and see things differently and this is not something you can live with, let's talk in a healthy way."
Another small note: I wouldn't even bring up that you're trying to improve her life. You have the right to improve your own life and experience and that's enough. Including her in that opens the door for her to say "I don't want you to do that for me." which is not relevant in this case as long as there has been no history of side effects of the meds causing problems for those around you.