Reformatted means you probably deleted your public and private ssh keys (in ~/.ssh).
You need to regenerate them and publish your public ssh key on your BitBucket profile, as documented in "Use the SSH protocol with Bitbucket", following "Set up SSH for Git with GitBash".
Accounts->Manage Accounts->SSH Keys:
Then:
Images from "Integrating Mercurial/BitBucket with JetBrains software"