change sequence settings from 720p to 1080p
I'm new to premiere but Ive spent several days creating a short film only to find that the sequence settings were set to 720p which prevented me from rendering the video in 1080p. When I went into sequence settings and tried to change it, all of my clips got really small and when it renders, its basically an animated thumbnail in the middle of the screen. Is there a way to fix this is Adobe premiere cc 2017? Ive searched and tried everything but I'm afraid I'm going to have to start over and flush 20+hours of work down the drain.

