I accidentally marked all mails as junk, how to undo?

Hello,

I wanted to mark all the mails as read, so I clicked edit -> select all -> but accidentally I have taped on move to junk instead of mark as read. I didn’t get any confirmation for this bulk action and how do I undo this action now. I already have lot of junk mails in my junk folder and all my mails also went into junk. Sorting them out is a nightmare. Is there a easy way to undo my action? Or modify settings so that I get a confirmation when I do bulk actions on mail