git reset –hard origin/master
says: throw away all my staged and unstaged changes, forget everything on my current local branch and make it exactly the same as origin/master.
You probably wanted to ask this before you ran the command. The destructive nature is hinted at by using the same words as in “hard reset”.
In newer version of git (2.23+) you can use:
git switch -C master origin/master
-C is same as –force-create. Related Reference Docs