Help! I just deleted all emails by mistake!

I deleted my emails accidentally in all folders! I was trying to clean up a huge amount of repeat emails I discovered under my gmail 'archive' list of emails, and selected all under this tab (I thought) and deleted the lot since they were not what I hoped to find there. I was looking for certain emails I thought I had archived so I didn't lose them, there were not there, instead lots of repeats from my notepad. I therefore did the deletion but now wish I hadn't. I know my lost emails will still be on my server? also that I have a back up system via a Samsung plugged in box, so I should be ok? but how do I get them back in?

I also have an iPad, same problem of course.