Are you aware that your instance is currently home to nearly 20,000 users, while still only reporting just 2 posts? From the outside looking in your instance looks like the current home of a spam bot farm waiting to happen.
Most of those users seem to have joined in the past 2 days. https://fedidb.org/network/instance/lemmy.elest.io
Yeah looks like a lot of single-user instances have seen a similar huge surge in user accounts. Here is a link to one of the discussions on the topic: https://lemm.ee/post/177673