One of the reasons why there aren´t dozens of MAP communities around is because the MAP community isn´t that big, even if you could create your own instance it would be a struggle to attract users and start from zero.

I can´t recommend you any other forum but since I also have a few health problems I can recommend you what has helped me out the most, disconnecting online and finding something to do outside, I am lucky enough to live in beautiful surroundings far from the city and going walking with others has been great but it can be anything you enjoy, there are other free activities like volunteering for a dog shelter, crochet, etc. I would not call being online "socialising", although you can´t tell anybody offline that you are a MAP because it would end up badly it is still positive to stay around other people doing something you enjoy.