Revert a Draft page to its original version

I recently went into my Main Page to make some changes, and my inexperience with the new block mode caused me to mess it up. However, I had saved the messed-up version as a Draft.

Now, I want to get rid of the draft and revert it back to where it was before I made those changes. But I can't find any way to get rid of the changes I had made, so now my page is stuck as a Draft because I can't publish it as it is.

If I can't revert my page back to the pre-Draft version, then I will re-build it.

I have learned too late to make a duplicate of a page before going in to muck with it. Lesson learned.

In the meantime, if there's a way to revert my page back to the pre-Draft version, please point me in the right direction.

Thanks