If LJ disappears without notice, I'm still "goddess47" on both Dreamwidth and Insane Journal... so come and find me there, if you need.
And, if you have things on your LJ that you'd like to keep, there is an LJ archive program that seems to work fairly well.
LJArchive - downloadable here: https://sourceforge.net/projects/ljarchive/ -- is simple to install and run... there is a ljarchive comm where there are comments about problems with downloading comments, so I skipped that for the moment in favor of having at least my posts. It's an older program, but installed and ran on my Win 10 system with no problem. Not sure it runs on a Mac, you'll have to poke at it.
It only took minutes to download 500 some posts that started Christmas 2007 (!)... My LJ has fic I've written that I really don't have anywhere else...
The program will also archive communities -- have to try that next to see how it works.
What it doesn't do is copy things that I've posted elsewhere on other comms or where fest mods have posted for me... so there are a couple (okay, lots!) of things that I'm going to search for this weekend (since I have no New Year Eve plans).
But I'm sticking around -- there are things comms / people here that I don't have contact with anywhere else...