The key it spits out does not match the key that is present on my github accoun
The idea of ssh key is not to reuse a public and private key pair, but to have one for each specific environment from which you are pushing to GitHub.
Once you have generated an id_rsa (private) / id_rsa.pub (public) pair, public the public key on GitHub.
Test if that works with a:
ssh -T git@github.com