The attack shouldn't have exposed passwords or hashes, only the JWT cookie. The secret on the server has been changed so all old cookies should no longer work.

There is a very small possibility that email address may have been able to be seen if they logged is as you, but they were looking for admin accounts

Hi there! Looks like you linked to a Lemmy community using an URL instead of its name, which doesn't work well for people on different instances. Try fixing it like this: !fediverse@lemmy.ml