New public key
I use a Nitrokey to generate and store my private key. The key never leaves the device and no other copy exists. Usage of the key is protected by a rate-limited PIN code. The only way it could get compromised is someone taking the Nitrokey and beating the PIN out of me.
This private key is also used to sign the boot files on my computer. When re-flashing my Heads install, I answered some of the prompts without fully comprehending my actions and accidentally wiped my private key.
I no longer have access to it and needed to generate a new one. This new key is signed by an older key, which is known to several of my contacts. It is also signed using my Qubes Documentation Signing Key, which in turn was previously signed by the lost key.