So this is a relatively common problem I take it. This is the second time my site has just disappeared with all my setup, history, and contacts (pod.jns.im now nota.404). Did I miss something? Some sort of backup and transfer mechanism?
I’m afraid there’s nothing you can do when your pod is down. You need your private encryption keys, and those are stored in your pods database and not shared with anyone. Without those keys, you cannot prove that you are who you claim you are, so there’s nothing you can do.
If the pod comes back up, go to your account settings and start an export. That’s not perfect, and you can’t quite use it for anything just yet, but having that backup somewhere is better than not having it.