Accidentally deleted email

I had a similar problem to an earlier question in that I had saved a partly written email in drafts and went back later and continued writing it. I then accidentally highlighted the entire text and compounded my mistake by accidentally mis-hitting the keyboard and was left with a blank email containing the letter “y”.

I tried to get back to where I had been but could only get back to the original draft email I’d started with so lost the considerable amount of text I had just put in. Any solution to that?