I was diagnosed at 34, primarily inattentive type.
Prior to that, I could excel in academics and my career IFF it was interesting or challenging. When it wasn’t, I couldn’t bring myself to focus. After diagnosis and medication, suddenly I could just do stuff. The best part is that my ability to hyper-focus on interesting work didn’t diminish, something I think most people fear when starting medication for ADHD.
I started on Adderall XR, which worked fine for a while. A better way to say that would be that I got used to feeling normal, and so was more aware of when I wasn’t. I noticed that it was wearing off right when I needed it the most, mid-late afternoon. In theory it’s a 12 hour release, but my psych said most people don’t experience that.
So, I shifted to Mydayis, which is the exact same drug, but with a triple release so it lasts longer. They claim 16 hours; IME it’s more like 10, but YMMV.
The other thing to be aware of is that depression is often correlated with ADHD. I was diagnosed with mild depression, but didn’t really think it was a big deal (I felt happy enough), so I didn’t treat it. Then this last winter came. I’ve been aware that I have seasonal affective disorder for years, and have always treated it with Vitamin D supplements. That didn’t work this year. I then bought a light therapy box, which also didn’t work. I already exercise regularly, so that wasn’t it either. I went back to my psych, who recommended Wellbutrin XL, at the smallest dose. As an aside, this also has an off-label use for treating ADHD if you’d rather not use stimulants. After precisely 13 days of being on it, I realized I did not feel mopey, despite it being a gloomy day. It was incredible.
I tried coming off Wellbutrin this spring, and it did not go well. My thought, and my wife’s, is that I had forgotten my previous baseline mood, and so it was a shock to realize the difference. AFAIK, and according to my psych, there are no known long-term effects from Wellbutrin, and I’ve exhibited zero of the known side effects, so I’m just on it for the foreseeable future.
Hope that helps, and I hope you seek professional help. Anecdotes are great for getting a variety of opinions, but they’re no substitute for a trained medical professional.