↩ reply to @cecton oof, good job kitty.
You might already know about them but if not, Neovim has some features that can recover from these situations. There's undolist (
https://neovim.io/doc/user/undo.html#%3Aundolist) for accessing the undo tree, but it's more easily used via
https://github.com/mbbill/undotree. There's also
https://neovim.io/doc/user/undo.html#undo-persistence for persisting the undo tree even after exiting.