So, your image is now within the limits and should be returned to it's proper gallery.
The screenshot above show two areas of the "Edit this gallery" page. Again, from the "Whoops"-gallery (thumbnail-view) you choose "Edit this gallery".
Scroll to your image and tick the box. Tick only your own image and continue to scroll down untill you see the "Move selected items to Another Gallery" option.
Use the drop-down menu to choose the gallery name you wrote down just a minute ago. Finish by clicking the "Add to Gallery" button.
Good, you're done, your image is back where it should be and now it's also the right size.
Thanks a lot for your cooperation!