Gpg key lost in self update

[doark at mail.com]

Hello,
I used a config file (hand written), and concatenated several of it's
lines to form a super long strong passphrase for my key.
Bad news is that I foolishly changed the file and lack an old enough
backup to find the original one.
Now, I've read that you could use a program to crack the private key and
I'd rather not create a new key since my original was never compromised.
Do you know of any I might use?

Thanks,
David