Outlook folders not syncing

I use an imap account to sync my email account between a laptop, pc, iPhone and iPad. The laptop uses Windows 8 and the pc uses Windows 7. The problem: I noticed that some sub-folders on the laptop were not syncing with the pc. I checked the imap settings and found that those folders were not “subscribed”, so I subscribed and did a send and receive. The result was that the folders (along with all of the emails in them) disappeared from all of my devices; they were not even in deleted items! Can anybody shed any light on why this happened and how to avoid it in the future please? I don’t back up the Outlook account separately as I assumed that syncing with the server was my backup! But is there anyway of going back to Outlook as it was a few days ago? The laptop uses Office 2013 and the pc uses 2010. Thanks for any help or advice that you can provide.