Full disclosure, I'm not officially diagnosed yet, but hopefully will be within a few weeks.
I stream and, as you'd expect, most of the other streamers I follow and get along with are either openly neurodivergent or I notice the signs. The tags I've seen include Autism, ADHD, AuDHD, Neurodivergent, and task related keywords like Body Doubling. I would also say that the game matters. If you are looking for games you're already into, chances are they probably appeal to other neurodivergent folk as well. But if you're more interested in fun people and good communities regardless of game, the factory games like Factorio and Satisfactory are an obvious gold mine.
I'd rather not post my channel as I'm not trying to advertise and I keep it separate from my other online accounts, but I think the above should dig up plenty. If not, I might be able to give suggestions if I knew more about what you're looking for. It depends on how familiar I am with it. I don't really follow a lot of popular games or streamers.
I can't help with your primary request, but on the chance that you aren't able to find a better solution, it seems worth mentioning that four months is probably too long. I'm not an expert or anything, but I did look into it when I had to take a drug test. If someone has corrections to what I found, I would be interested to hear them because it may not be the last I have to deal with it either.
What I learned is that exact time varies, but two months is on the long end. One month is common. You can even test negative in as little as two weeks, but it requires specific effort and still might not be enough if the test is really strict or sensitive.
There are a lot of tricks for trying to quickly prepare for a drug test, but the most simple and reliable if you aren't on a major time crunch is just fiber and water. Eat lots of greens and stay hydrated. That helps your body naturally get rid of the THC, making 3-4 weeks a more likely time frame.
If he's already suffering through a detox, you can at least shorten that by quite a bit. Also, it will get easier over time. While weed is way less addictive and easier to get off of than a lot of other drugs, it still has side effects like the ones you're describing when you try to quit.
I still hope you find a better doctor, but don't lose hope even if you can't. This is doable and it's not as impossible as it seems. It is bullshit and unfair though. Best of luck to you both.