I just committed the wrong source to my project using -FORCE.
Is it possible to revert? I understand that all previous branches have been overwritten using -f, so I may have screwed up my previous revisions.
Git generally doesn't throw anything away, but recovering from this may still be tricky.
If you have the correct source then you could just push it into the remote with --force. Git won't have deleted any branches unless you told it to. If you have actually lost commits then take a look at this useful guide to recovering commits. If you know the SHA-1 of the commits you want then you're probably OK.
Best thing to do: Back everything up and see what is still in your local repository. Do the same on the remote if possible. Use
git fsck to see if you can recover things, and above all DO NOT run
Above above all, never use --force unless you really, really mean it.