Lemmy active users grew by an astounding 1600% in June
From 2,997 active users across all lemmy instances at the beginning of June, the number increased to 52,797 by June 30th. Source.
An active user on Lemmy is "someone who has posted or commented on our instance or community within the last given time frame.” Source. That means lurkers are not counted as active users.
I hope more communities move to lemmy, especially the mental health/support ones.
As for lemmy in general, I have to say that apart from the lack of videos, it's not bad at all, even the android apps are already better than the official reddit one (terribly slow for some reason).
Check that your instance is correct (lemmy.world) and try again when the server works better.
Right now the server seems to be having a lot of trouble loading pages, etc, and maybe that's why it's not working for you.