Dianne, there is no need to attempt to commit again because the local repo attached to your project is likely up to date so will tell you there is no changes to commit.
If you follow the steps in creating a fresh GitHub repository and attach that to your existing project as I described, all you need to do is use the Xcode menu and select Source Control then Push…. Do not attempt to create a new commit. The Push menu option will transfer all of the individual commits up to the new Gihub repo.
IF after the Push up to GitHub the new repo still does not show all of your files (I would be surprised if that were the case) then there is obviously a problem with your local repo attached to your project. We will cross that bridge when we get to it.