BitcoinOllie on Nostr: Ok, @kieran. How do I change a Hexidecimal number back into my nsec private key or is ...

Ok, @kieran. How do I change a Hexidecimal number back into my nsec private key or is it now long gone. I am using nos2x but only have a weird sequence of numbers whereas my npub remains normal looking? Thank you for any help I receive or should I just set up a new profile?