after updating my iMac/Iphone lost all mail

I recently updated by Imac and Iphone to ios 7.1, now I have lost all the mail before that date on my computer. Until a moment ago I have all my saved Mail on my iphone (that is ones put into folders) still there but as I was sittting next to the computer when I opened the mail boxes on my iphone I saw it disappear!!!! I got a lovely message saying "updated". I had keep these for a reason as they were important to me, now I have nothing there!!!!! Anyone else had this problem. By the way I was using google gmail account.