At this point, a Fuss is all you have. if the web lets you "add a nameserver" there's a path out where you get a nameserver somebody you trust runs, to get a copy of the zone, and use "bind" journal de-compile tools to see it in plaintext

Depending on how long you have had the zone, re-delegating it through another registrar may be timelocked. Its a bit of a shit-show.

You are on a steep learning curve or need consultant/contractor help (which btw I cannot do, sorry)