I would recommend avoiding any subreddit related to ADHD.

I honestly would try to stick to materials written by mental health professionals and possibly talking to a therapist (your company might have an EAP that can help with this) over interacting with any online community I'm aware of on this matter.

I find online mental health communities tend to be "if I have a hammer, everything is a nail," and aren't open to other explanations for any traits or struggles. They also tend to suck in the people who aren't doing better with treatment, while the people who found systems that work for them leave for greener pastures. On the opposite side there are communities that are anti-psychiatry and refuse to consider medical treatments. In general these spaces tend to be very black and white.

I do like the Astral Codex Ten open threads as a space that's relatively neutral on the topic, though they lean very biohacker in a way that gets ahead of the science.