After restarting my computer I went to commit and receive this message:

error: bad signature

fatal: index file corrupt

running 'git branch':

fatal: Failed to resolve HEAD as a valid ref.

running 'git log':

fatal: your current branch appears to be broken

How can I restore/fix my local repo/branch?

After restarting my computer, 'git commit' & 'git status' both return an error message:

error: bad signature

fatal: index file corrupt

running 'git branch':

fatal: Failed to resolve HEAD as a valid ref.

running 'git log':

fatal: your current branch appears to be broken