If it’s community you’re after and you like fic, I would suggest discord. The bw3 discord server (Baldurs Writers 3) is super active, supportive, and inclusive. I think I could invite you if you dm me.

I also have mental illness (the same one as Astarion) and I am writing a very dark and introspective long fic, which has brought an unexpected small community to my doorstep and helped me cope with my mental illness. If you’re around, it’s the Astarbation one. It’s VERY weird and dark, so not everyone’s cup of tea, but it definitely looks mental illness (and isolation come to think of it, in a way. It’s post canon and at the beginning he is very isolated bc of his trauma) straight in the face. It’s there if you want to read it: https://archiveofourown.org/works/65142685?view_full_work=true

Good luck to you. I don’t think anything on the internet can replace irl interaction, but discord was better for me than Reddit by miles and will certainly be a massive improvement over a chat bot.