As you probably know, twitter isn't looking that great in these days. I don't think it's gonna go anytime soon, but many artist are already preparing themself creating plans B with other platforms so I might do it too.
These are the options I've concidered (aside from FA since I'm already pretty active here):

Tumblr:
The most famous one, unfortunatly doesn't allows porn as you all know... but allows nudity. You can argue with the fact that my stuff isn't that explicit, but still I'm not bringing fetish stuff on a SFW site. Might use it for other SFW projects and to keep contact with other artist, but yeah that's it.

Deviant art:
Same as tumblr, but kinda worst, plus FA works way better so not my choise

Pixiv:
Know nothing about it, but I heard you can post NSFW there soooo if someone knows more let me know

Mastodon:
Looks very interesting, it as most of the features you had with twitter and it had a download boost since the migration started, the only thing is that is pretty confusing to use concidering the decentralized nature of the site, would take soooo much for the comunity to actually get used to it and also still don't know what server I should go with and what server allows NSFW

Newgrounds:
Looks good, it would be just another gallery tbh, but better than nothing I guess

Other? Let me know and tell me your toughts about it

EDIT:

Pillowfort is also a choise, but it has no following whatsoever and I doubt the server are gonna andle the migration.
Also a little talk about discord: Now as a platform discord isn't a social like twitter, is just a place for comunityes to hang out, play games, chat and stuff, you can't really follow anyone or make a gallery to promote yourself as an artist, however I wouldn't mind to create a server for my follows to hang out and chill, plus discord is adding a few new features like homepage for every server, so that's interesting I guess.
Also I never used reddit, idk if you can do something with it, but let me know