Corrupted pages

I built my website years ago, and have updated it occasionally, but I have just noticed that one of the pages is all out of whack. Images missing, blocks have shifted, the menu items I included in the questionnaire seem to be blank, and the context is all gone because of the misplaced text blocks and images. 

Is there a way to retrieve an earlier version of this page?  I don't know how long ago this problem arose, but I think it was just a few months ago.