My Mastodon instance disappeared. Now what?

I joined mastodon.xyz a few years ago and never had any problems. Then today I tried to sign on and couldn’t. The server simply isn’t reachable. I can (and have) created a new instanceuaccount on a new server, but losing all my data has me concerned. What should I do with my new account so I don’t lose everything if this instance also disappears someday?