You could always do:

  git reflog

to see when you last checked out master, then:

  git reset <commit hash> --soft

to reset to the commits at that point (but keep your files the same)

  git add . && git stash save

to stash your changes (not 100% sure you actually need the "git add ." part)

  git pull

in master

and then finally:

  git stash pop

and commit again as needed.