how to recover draft in Hotmail/outlook original from yesterday, that was edited today and saved today in error without the original text?

I had a saved draft(long letter) in my hotmail account...I went to work on it today, retrieved from drafts and was typing and it removed my entire document and typed the one word I was trying to add to the document.  It then saved with only that one word and I can't find the complete document.  How can I retrieve a draft, as it was saved earlier today, or yesterday?